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, Guler, S. Ilgin, Gayah, Vikash V., Menendez, Monica, 2016 >>
Autor(en): Guler, S. Ilgin, Gayah, Vikash V., Menendez, Monica
Titel: Bus priority at signalized intersections with single-lane approaches: A novel pre-signal strategy
Kurzbeschreibung: Signalized intersections often represent a major source of bus delays in urban environments. One strategy to mitigate this problem is to dedicate an existing car lane for bus-use only and use an additional signal to help minimize interactions between cars and buses. However, this is physically impossible at approaches where only a single travel lane is available for each direction. To this end, this research explores a novel method to provide priority to buses at signalized intersections with single-lane approaches that (nearly) eliminates bus delays while minimizing the negative impacts imparted to cars. Using additional signals to stop cars on the opposing travel lane, the bus can jump a portion of the car queue using the travel lane in the opposite direction. This paper theoretically quantifies the delay savings buses can achieve, and the negative impacts imparted onto cars when this pre-signal strategy is applied. The negative impacts are measured as the additional car delays experienced when the intersection signal is under-saturated, and the reduction in car-discharge capacity when the intersection signal is over-saturated. In the under-saturated case, the results show that moderate average bus delay savings (~~5–7 s per vehicle, equivalent to about 25% of the average delay expected at the intersection) are achieved if the pre-signal is always in operation and the total passenger delay is decreased only if bus occupancies are very high. However, if the pre-signal operation is targeted to only provide priority to the buses that would benefit the most, bus delay savings can be more than doubled while reducing the total passenger delay, even if the ratio of bus to car occupancy is relatively modest (greater than about 20). In the over-saturated case, bus delay savings can be much more significant (greater than 30 s per bus), and this delay saving can increase further for longer block lengths (greater than 100 m). However, the capacity of the intersection decreases by up to 25% during each cycle in which a bus arrives to the intersection. Simulation tests confirmed that the general trends and magnitudes of bus delay savings and negative impacts to cars hold for more realistic behaviors. The overall benefits are slightly smaller in the simulations, but nevertheless the strategy seems promising as a bus priority strategy at intersections with single-lane approaches in the field.2
Publiziert in: Transportation Research Part C: Emerging Technologies
Band: 63
Seiten: 51 - 70
Publikationsdatum / Empfangsdatum: 2016-01-01
Publikations-Status: Published online
Sprache: English
DBID Quelle: FORM-1451807612, SCOPUS-84951744047
DOI: 10.1016/j.trc.2015.12.005
, Sasidharan, Lekshmi, Wu, Ke-Feng, Menendez, Monica, 2015 >>
Autor(en): Sasidharan, Lekshmi, Wu, Ke-Feng, Menendez, Monica
Titel: Exploring the application of latent class cluster analysis for investigating pedestrian crash injury severities in Switzerland
Kurzbeschreibung: One of the major challenges in traffic safety analyses is the heterogeneous nature of safety data, due to the sundry factors involved in it. This heterogeneity often leads to difficulties in interpreting results and conclusions due to unrevealed relationships. Understanding the underlying relationship between injury severities and influential factors is critical for the selection of appropriate safety countermeasures. A method commonly employed to address systematic heterogeneity is to focus on any subgroup of data based on the research purpose. However, this need not ensure homogeneity in the data. In this paper, latent class cluster analysis is applied to identify homogenous subgroups for a specific crash type-pedestrian crashes. The manuscript employs data from police reported pedestrian (2009-2012) crashes in Switzerland. The analyses demonstrate that dividing pedestrian severity data into seven clusters helps in reducing the systematic heterogeneity of the data and to understand the hidden relationships between crash severity levels and socio-demographic, environmental, vehicle, temporal, traffic factors, and main reason for the crash. The pedestrian crash injury severity models were developed for the whole data and individual clusters, and were compared using receiver operating characteristics curve, for which results favored clustering. Overall, the study suggests that latent class clustered regression approach is suitable for reducing heterogeneity and revealing important hidden relationships in traffic safety analyses.2
Publiziert in: Accident Analysis and Prevention
Band: 85
Seiten: 219 - 228
ISSN: 0001-4575, 1879-2057
Publikationsdatum / Empfangsdatum: 2015-12-01
Publikations-Status: Amsterdam
Publikations-Status: Published
Einordnungen: Binary logit, Cluster analysis, Latent class, Pedestrian, Receiver operating characteristic (ROC) curve, Severity, Switzerland
Sprache: English
Schlüsselwort: Binary logit, Cluster analysis, Latent class, Pedestrian, Receiver operating characteristic (ROC) curve, Severity, Switzerland
DBID Quelle: FORM-1445672996, SCOPUS-84944062678, WOS-000364884800021
DOI: 10.1016/j.aap.2015.09.020
Nebis System Nummer: 000041481
, Guler, S. Ilgin, Menendez, Monica, 2015 >>
Autor(en): Guler, S. Ilgin, Menendez, Monica
Titel: Pre-signals for bus priority: basic guidelines for implementation
Kurzbeschreibung: When compared to cars, public transportation (e.g., buses) can carry more people using less space. Hence, by increasing the share of people traveling by bus within an urban network, we can improve the efficiency of the urban transportation system, ultimately making it more sustainable. Unfortunately, buses operating mixed with cars can often get stuck in car congestion. One commonly used solution is to dedicate a lane for bus-use only. However, when bus flows are low, dedicated lanes running through intersections can reduce the discharge flows from these locations and lead to increased car delays, car queues, and all the negative externalities associated with congestion. This, in turn, can reduce the overall efficiency of the transportation network. Therefore, a solution is to discontinue the dedicated lane upstream of the main signal, removing bus priority at intersections. In this paper, we advocate the use of pre-signals upstream of signalized intersections to continue providing bus priority while minimizing the disruptions to car traffic. Pre-signals can allow buses to jump the car queues upstream of signalized intersections, while allowing cars to utilize the full capacity of the main signal when buses are not present. In this paper we provide practical guidelines on how to implement pre-signals at signalized intersections. Ideas on how to operate pre-signals are provided by using recent analytical and empirical findings from previous research on pre-signals. The reduction of system-wide (buses and cars) person hours of delay by using pre-signals, as compared to mixed-use lanes or dedicated bus lanes is also quantified. By doing so, the domains of application of pre-signals are also defined. This information can then be used to determine where and when pre-signals should be implemented in real urban networks and to quantify their benefits to the system.2
Publiziert in: Public Transport
Band: 7
Ausgabe: 3
Seiten: 339 - 354
ISSN: 1866-749X, 1613-7159
Publikationsdatum / Empfangsdatum: 2015-12-01
Publikations-Status: Dordrecht
Publikations-Status: Published
Einordnungen: Pre-signals, Bus priority, Traffic flow, Signalized intersections
Sprache: English
Schlüsselwort: Pre-signals, Bus priority, Traffic flow, Signalized intersections
DBID Quelle: FORM-1392995631, SCOPUS-84949219324
DOI: 10.1007/s12469-015-0104-9
, Cao, Jin, Menendez, Monica, 2015 >>
Autor(en): Cao, Jin, Menendez, Monica
Titel: System dynamics of urban traffic based on its parking-related-states
Kurzbeschreibung: The urban parking and the urban traffic systems are essential components of the overall urban transportation structure. The short-term interactions between these two systems can be highly significant and influential to their individual performance. The urban parking system, for example, can affect the searching-for-parking traffic, influencing not only overall travel speeds in the network (traffic performance), but also total driven distance (environmental conditions). In turn, the traffic performance can also affect the time drivers spend searching for parking, and ultimately, parking usage. In this study, we propose a methodology to model macroscopically such interactions and evaluate their effects on urban congestion.

The model is built on a matrix describing how, over time, vehicles in an urban area transition from one parking-related state to another. With this model it is possible to estimate, based on the traffic and parking demand as well as the parking supply, the amount of vehicles searching for parking, the amount of vehicles driving on the network but not searching for parking, and the amount of vehicles parked at any given time. More importantly, it is also possible to estimate the total (or average) time spent and distance driven within each of these states. Based on that, the model can be used to design and evaluate different parking policies, to improve (or optimize) the performance of both systems.

The model is built on a matrix describing how, over time, vehicles in an urban area transition from one parking-related state to another. With this model it is possible to estimate, based on the traffic and parking demand as well as the parking supply, the amount of vehicles searching for parking, the amount of vehicles driving on the network but not searching for parking, and the amount of vehicles parked at any given time. More importantly, it is also possible to estimate the total (or average) time spent and distance driven within each of these states. Based on that, the model can be used to design and evaluate different parking policies, to improve (or optimize) the performance of both systems.

A simple numerical example is provided to show possible applications of this type. Parking policies such as increasing parking supply or shortening the maximum parking duration allowed (i.e., time controls) are tested, and their effects on traffic are estimated. The preliminary results show that time control policies can alleviate the parking-caused traffic issues without the need for providing additional parking facilities. Results also show that parking policies that intend to reduce traffic delay may, at the same time, increase the driven distance and cause negative externalities. Hence, caution must be exercised and multiple traffic metrics should be evaluated before selecting these policies.

Overall, this paper shows how the system dynamics of urban traffic, based on its parking-related-states, can be used to efficiently evaluate the urban traffic and parking systems macroscopically. The proposed model can be used to estimate both, how parking availability can affect traffic performance (e.g., average time searching for parking, number of cars searching for parking); and how different traffic conditions (e.g., travel speed, density in the system) can affect drivers ability to find parking. Moreover, the proposed model can be used to study multiple strategies or scenarios for traffic operations and control, transportation planning, land use planning, or parking management and operations.2
Publiziert in: Transportation Research Part B, Methodological
Band: 81
Ausgabe: 3
Seiten: 718 - 736
ISSN: 0191-2615, 1879-2367
Publikationsdatum / Empfangsdatum: 2015-11-01
Publikations-Status: Amsterdam
Publikations-Status: Published
Einordnungen: Verkehr und Transport|Traffic and Transportation, Macroscopic parking model, Traffic congestion, Parking-related traffic state, Cruising-for-parking, System dynamics of urban traffic
Eventname: 21st International Symposium on Transportation and Traffic Theory (ISTTT 21)
Eventdatum: August 5-7, 2015
Ort: Kobe, Japan
Sprache: English
Schlüsselwort: Macroscopic parking model, Traffic congestion, Parking-related traffic state, Cruising-for-parking, System dynamics of urban traffic
DBID Quelle: FORM-1437811524, SCOPUS-84947494851, WOS-000366237900006
DOI: 10.1016/j.trb.2015.07.018
Nebis System Nummer: 000006554
, Roca-Riu, Mireia, Ge, Qiao, Menendez, Monica, 2015 >>
Autor(en): Roca-Riu, Mireia, Ge, Qiao, Menendez, Monica
Titel: Methodology for generating extreme traffic demand patterns with optimization techniques
Kurzbeschreibung: Traffic scenario generation can aid analyzing and evaluating the performance of transportation systems under different traffic conditions. Unfortunately, it has not drawn much attention in practical applications. No standard scenario generation approach can be found so far, other than manual generation, random generation or exhaustive generation, which are neither accurate nor efficient.
Given its importance, we propose to borrow ideas from optimization techniques to solve the optimization problems in generating representative and/or extreme traffic scenarios. In this paper, five optimization methods, i.e., Linear Programming (LP), Dynamic Programming (DP), Greedy Algorithm (GR), Genetic Algorithm (GA), and Tabu Search (TS), are introduced and implemented to generate extreme traffic demand patterns.
The accuracy and efficiency of these methods are explored with a case study, in which the best and worst traffic demand patterns are searched for an abstract grid network. It is found in the case study that when the problem uses an independent traffic assignment model (e.g., shortest path assignment), LP and DP are the most accurate methods. GR is the most efficient method. GA presents certain accuracy when searching for best demand patterns, while TS is more accurate when searching for worst demand patterns. Moreover, GR, GA, and TS do not require linear constraints and objective functions, thus they could also work with other dependent traffic assignment models if computational times become affordable. Considering the overall performance (accuracy, efficiency, and constrains in application), GR is recommended as the best methods for generating extreme demand patterns.2
Publikationsdatum / Empfangsdatum: 2015-04-01
Publikations-Status: Ascona
Publikations-Status: Published
Einordnungen: Demand pattern generation, Demand Scenario, Traffic Assignment, Traffic Networks
Eventname: 15th Swiss Transport Research Conference (STRC 2015)
Eventdatum: April 15-17, 2015
Ort: Ascona, Switzerland
Sprache: English
Schlüsselwort: Demand pattern generation, Demand Scenario, Traffic Assignment, Traffic Networks
DBID Quelle: FORM-1432376024
, Ge, Qiao, Menendez, Monica, 2015 >>
Autor(en): Ge, Qiao, Menendez, Monica
Titel: Sampling dependent parameters in traffic simulation models with Gaussian copula
Kurzbeschreibung: Making samples with certain marginal distributions and dependence structures is an essential but difficult step to perform sampling-based SA for traffic simulation models with dependent parameters. In this paper, we present a general approach for generating samples for dependent parameters. It utilizes the Gaussian copula in the sampling process, which makes it attractive for sampling parameters from any arbitrary marginal distribution. Furthermore, the Spearman's rank correlation coefficient is employed instead of the traditional linear correlation coefficient, so that the dependence structure of the empirical data can be retained throughout the non-linear transform of the Gaussian copula.
A case study that generates samples for the kinematic parameters of Wiedemann-74 car-following model is included to demonstrate the application of this approach. It has shown that the marginal distributions and correlation coefficients of the generated samples are comparable with that of the empirical data. Specifically, the 1,024 samples, which are generated by employing the Sobol sequence in the sampling process, also present consistent marginal distributions and correlation coefficients as the empirical data. This has demonstrated that the proposed sampling approach is also useful for making proper samples of computationally expensive models, for which a big number of model runs are not always affordable.2
Publikationsdatum / Empfangsdatum: 2015-04-01
Publikations-Status: Ascona
Publikations-Status: Published
Einordnungen: Data Sampling, Dependent Parameters, Gaussian Copula, Traffic Model
Eventname: 15th Swiss Transport Research Conference (STRC 2015)
Eventdatum: April 15-17, 2015
Ort: Ascona, Switzerland
Sprache: English
Schlüsselwort: Data Sampling, Dependent Parameters, Gaussian Copula, Traffic Model
DBID Quelle: FORM-1432373723
, Rothenfluh, Marco, Menendez, Monica, 2015 >>
Autor(en): Rothenfluh, Marco, Menendez, Monica
Titel: A Network Safety Management (NSM) tool for improving traffic safety in Zurich
Kurzbeschreibung: Due to the great number of traffic accidents, it is essential for road administrators to know where some investments are necessary to improve the system. Network Safety Management (NSM) is a tool, based on the number of accidents, to detect locations with the highest potential for improving the road infrastructure. The area of study is the city of Zurich and the accidents in the period 2009 to 2013 are used.
The aim of the work is to properly analyse the existing results for NSM and to test different variations of input parameters. Information about the robustness of the model for inner urban areas should be provided. For that, the existing road network is explored in order to have an explicit distinction between traffic oriented roads and residential roads. On the basis of the assumptions of different accident cost rates, the avoidable accident cost per year is calculated and a prioritization of the three road network elements traffic oriented roads, nodes and residential zones is made. The results show that mostly network elements with numerous conflict points have the highest infrastructure potential for improving traffic operation. Due to the great sensitivity of the model parameters, different samples of inputs are tested. Not only new cost rates for the city of Zurich are calculated, but also a variation of the size of nodes, the traffic volume and the aggregation of section creation are examined.
Furthermore, an overlay with the widely adopted road safety tool of Blackspot Management (BSM) is done to verify the detected accident clusters. The findings are used to make pragmatic recommendations on the use of NSM as a safety analysis tool.2
Publikationsdatum / Empfangsdatum: 2015-03-01
Publikations-Status: Ascona
Publikations-Status: Published
Einordnungen: Network Safety Management (NSM), Infrastructure potential, Accident cost, Sensitivity analysis
Eventname: 15th Swiss Transport Research Conference (STRC 2015)
Eventdatum: April 15-17, 2015
Ort: Ascona, Switzerland
Sprache: English
Schlüsselwort: Network Safety Management (NSM), Infrastructure potential, Accident cost, Sensitivity analysis
DBID Quelle: FORM-1432376954
, Ge, Qiao, Ciuffo, Biagio, Menendez, Monica, 2015 >>
Autor(en): Ge, Qiao, Ciuffo, Biagio, Menendez, Monica
Titel: Combining screening and metamodel-based methods
Untertitel: An efficient sequential approach for the sensitivity analysis of model outputs
Kurzbeschreibung: Sensitivity analysis (SA) is able to identify the most influential parameters of a given model. Application of SA is usually critical for reducing the complexity in the subsequent model calibration and use. Unfortunately it is hardly applied, especially when the model is in the form of a computationally expensive black-box computer program. A possible solution concerns applying SA to the metamodel (i.e., an approximation of the computationally expensive model) instead. Among the other options, the use of Gaussian process metamodels (also known as Kriging metamodels) has been recently proposed for the SA of computationally expensive traffic simulation models. However, the main limitation of this approach is its dependence on the model dimensionality. When the model is high-dimensional, the estimation of the Kriging metamodel may still be problematic due to its high computational cost. In order to overcome this problem, in the present paper, the Kriging-based approach has been combined with the quasi-optimized trajectory based elementary effects (quasi-OTEE) approach for the SA of high-dimensional models. The quasi-OTEE SA is used first to screen the influential and non-influential parameters of a high-dimensional model; then the Kriging-based SA is used to calculate the variance-based sensitivity indices, and to rank the most influential parameters in a more accurate way. The application of the proposed sequential SA is illustrated with several numerical experiments. Results show that the method can properly identify the most influential parameters and their ranks, while the number of model evaluations is considerably less than the variance-based SA (e.g., in one of the tests the sequential SA requires over 50 times less model evaluations than the variance-based SA).2
Publiziert in: Reliability engineering & system safety
Band: 134
Seiten: 334 - 344
ISSN: 0951-8320
Publikationsdatum / Empfangsdatum: 2015-02-01
Publikations-Status: Barking
Publikations-Status: Published
Einordnungen: Ingenieurwesen und Innovation|Engineering and Innovation, Sensitivity analysis, Variance-based approach, High-dimensional and computationally expensive model, Screening, Metamodel
Sprache: English
Schlüsselwort: Sensitivity analysis, Variance-based approach, High-dimensional and computationally expensive model, Screening, Metamodel
DBID Quelle: FORM-1393330841, SCOPUS-84913529830, WOS-000347663200035
DOI: 10.1016/j.ress.2014.08.009
Nebis System Nummer: 000473139
, Yang, Kaidi, Guler, S. Ilgin, Menendez, Monica, 2015 >>
Autor(en): Yang, Kaidi, Guler, S. Ilgin, Menendez, Monica
Titel: A transit signal priority algorithm under connected vehicle environment
Kurzbeschreibung: Transit signal priority is a cost-effective way to improve transit operations and reliability. Connected vehicles provide more precise and detailed information on vehicle movements, thus can be beneficial for transit signal priority. This paper proposes a transit signal priority algorithm using connected vehicle information. Simulation is conducted for different total flow, bus arrivals, bus occupancy and penetration rates. Results show that this algorithm successfully reduces the total passenger delay. It is also shown that this algorithm is not sensitive to the assumed occupancy, hence does not require accurate information on bus occupancy. Additionally, this algorithm significantly reduces the delay of buses with minimal increase to the delay of cars in the conflicting approach.2
Buchtitel: 2015 IEEE 18th International Conference on Intelligent Transportation Systems (ITSC) : proceedings
Seiten: 66 - 70
ISBN: 978-1-4673-6595-6
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Piscataway, N.J
Publikations-Status: Published
Eventname: 18th IEEE International Conference on Intelligent Transportation Systems (ITSC 2015)
Eventdatum: 15-18 September 2015
Ort: Las Palmas de Gran Canaria, Spain
Sprache: English
DBID Quelle: FORM-1446037784, SCOPUS-84950270968
DOI: 10.1109/ITSC.2015.19
, Yang, Kaidi, Guler, S. Ilgin, Menendez, Monica, 2015 >>
Autor(en): Yang, Kaidi, Guler, S. Ilgin, Menendez, Monica
Titel: A signal control strategy using connected vehicles and loop detector information
Kurzbeschreibung: Connected vehicle technology can be beneficial for the operations of intersections. The informa- tion provided by cars equipped with this technology can be used to design a more efficient signal control strategy. This paper builds on a previous signal control algorithm (Guler et al., 2014) that used position information provided by connected vehicle technology. This paper considers both connected and traditional vehicles and integrates the connected vehicle algorithm with loop detector information to better accommodate low penetration rates.

Simulations are conducted for different total flows, demand ratios, penetration rates and locations of loop detectors. Results shows that the proposed algorithm outperforms an actuated signal strategy for most scenarios tested. For low demand scenarios, both average number of stops and average delay decrease as there are more connected vehicles. For high demands scenarios, this algorithm requires less than 50% penetration rates to outperform the actuated algorithm. If the loop detectors are installed a certain distance away from the intersection (30m), the algorithm outperforms the actuated algorithm for all demands, demand ratios and penetration rates.2
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Ascona
Publikations-Status: Published
Einordnungen: Connected vehicles, Traffic control, Intersections, Loop detector information
Eventname: 15th Swiss Transport Research Conference, STRC 2015
Eventdatum: April 15-17, 2015
Ort: Ascona, Switzerland
Sprache: English
Schlüsselwort: Connected vehicles, Traffic control, Intersections, Loop detector information
DBID Quelle: FORM-1432377936
, Stempfel, Julie, Guler, S. Ilgin, Menendez, Monica, Brucks, Wernher M., 2015 >>
Autor(en): Stempfel, Julie, Guler, S. Ilgin, Menendez, Monica, Brucks, Wernher M.
Titel: Effects of urban congestion on safety of networks
Kurzbeschreibung: The objective of this work is to understand if on urban roads, traffic safety can be linked to traffic congestion. To do so, crash data for the network of Zurich, Switzerland, is linked traffic data describing congestion from the same network. By aggregating the data, the crash risk in relation to traffic states is analyzed: (i) over the entire network for different times of day; and (ii) for individual links with different congestion levels. It is found that at the network level, the crash risk (number of crashes per car) is higher during times when the average network speed is lower (5-7 pm). Lower speeds are observed during this time period typically due to congestion. Hence, at the network level, there is evidence for congestion being an indicator of increased crash risk. During the same (congested) time period, it is also observed that crashes mostly happen on links with medium speeds, which could be due to higher speed variations within individual links during the congested time periods.2
Publiziert in: Journal of Transportation Safety and Security
ISSN: 1943-9962, 1943-9970
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Philadelphia, PA
Publikations-Status: Accepted
Einordnungen: Safety, Urban Networks, Congestion
Sprache: English
Schlüsselwort: Safety, Urban Networks, Congestion
DBID Quelle: FORM-1424109270
DOI: 10.1080/19439962.2015.1007193
Nebis System Nummer: 006893087
, Soriguera, Francesc, Martínez Josemaría, Irene, Menendez, Monica, 2015 >>
Autor(en): Soriguera, Francesc, Martínez Josemaría, Irene, Menendez, Monica
Titel: Experimenting with dynamic speed limits on freeways
Kurzbeschreibung: This paper presents the design and first results of the Dynamic Speed Limit (DSL) experiment that took place on the last 13 km stretch of the B-23 freeway accessing the city of Barcelona (Spain). The DSL system installed, in addition to the high density of surveillance equipment available, makes this stretch a suitable highway lab. The objective of the experiment was to construct a comprehensive database of traffic engineering variables on a freeway site when different speed limits apply. Detailed measurements of vehicle counts, speeds, occupancies, lane changing maneuvers and travel times were taken. The potential of this multi-source database is huge. For instance, preliminary analysis empirically proves that drivers' compliance with dynamic speed limits is very limited, unless speed enforcement devices are present. In addition, in controlled sections with high compliance rates, it is observed that lowering the speed limit extends the range for critical occupancies beyond the typical values without changing the freeway capacity. This might be due to the observed reduction in the lane changing activity at these occupancy levels and for low speed limits. A direct consequence of this fact is that, even with a high compliance to very low speed limits (e.g. 40 km/h), the flow restriction imposed is insignificant. Stable flows near capacity are maintained together with very low speeds and very high densities. In practice, this means that the mainline metering capabilities of DSL are limited.2
Buchtitel: TRB 94th Annual Meeting Compendium of Papers
Seiten: 15-2729
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Washington, DC
Publikations-Status: Published
Eventname: 94th Annual Meeting of the Transportation Research Board (TRB 2015)
Eventdatum: January 11-15, 2015
Ort: Washington, DC, USA
Sprache: English
DBID Quelle: FORM-1446043494
, Saeednia, Mahnam, Taghizadeh, Gelareh, Menendez, Monica, 2015 >>
Autor(en): Saeednia, Mahnam, Taghizadeh, Gelareh, Menendez, Monica
Titel: Artificial immune systems for bus priority problem
Kurzbeschreibung: Prioritizing buses over other vehicles is one of the approaches for increasing the reliability of bus transportation in congested urban environments. However, assigning some lanes to buses reduces the available capacity of the network for cars. When dealing with this problem and in order to prevent a huge increase in the travel time of cars, the total travel time of the network should be considered. In this paper, the authors address the problem of prioritizing buses in an urban network using two types of meta-heuristic algorithms, Genetic algorithms and Artificial Immune Systems. The proposed methods applied to a real network, show that the Artificial Immune System performs better than the Genetic algorithm in terms of accuracy but it needs a higher number of iterations to converge.2
Seiten: 15-2343
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Washington, DC
Publikations-Status: Published
Eventname: 94th Annual Meeting of the Transportation Research Board (TRB 2015)
Eventdatum: January 11-15, 2015
Ort: Washington, DC, USA
Sprache: English
DBID Quelle: FORM-1446042684
, Saeednia, Mahnam, Menendez, Monica, 2015 >>
Autor(en): Saeednia, Mahnam, Menendez, Monica
Titel: Analysis of strategies for truck platooning: a hybrid strategy
Kurzbeschreibung: Trucks typically use the same infrastructure as cars and this imposes negative eects on the overall trac operations. To mitigate such eects as well as their negative environmental impacts, platooning of trucks can be considered as a potential solution. For platooning a set of trucks, two main strategies are assumed: a catch up strategy (i.e. the upstream trucks accelerate to catch up with the leading trucks) and a slow-down strategy (i.e. the leading trucks decelerate so that the upstream trucks can catch up and platoon with them). In this paper, the behavior of trucks when platooning using either of these two strategies is analyses. Then, a hybrid platooning strategy is developed that combines the two previously described approaches in an optimal manner. The performance of the hybrid strategy is further analysed and compared with that of the individual approaches. The results show that the hybrid strategy is the most general scheme capable of forming a platoon in various cases. Moreover, it is the fastest strategy considering the required time for platooning. In terms of performance, the hybrid strategy is capable of forming a platoon using the maximum platooning speeds of trucks. These, make it a suitable strategy for large-scale deployment in truck platooning.2
Publiziert in: SVT Working Paper
Band: 95
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Zürich
Publikations-Status: Published
Einordnungen: Truck platooning, Platooning strategies, Platoon coordination
Sprache: English
Schlüsselwort: Truck platooning, Platooning strategies, Platoon coordination
DBID Quelle: FORM-1429282984
, Ortigosa, Javier, Zheng, Nan, Menendez, Monica, Geroliminis, Nikolas, 2015 >>
Autor(en): Ortigosa, Javier, Zheng, Nan, Menendez, Monica, Geroliminis, Nikolas
Titel: Analysis of the 3D-vMFDs of the Urban Networks of Zurich and San Francisco
Kurzbeschreibung: In this paper we are studying the trade-off of urban road space dedicated to cars and buses (or trams) in two cities: Zurich and San Francisco. We employ the three-dimensional vehicle Macroscopic Fundamental Diagrams (3D-vMFD) which consist of creating the MFDs for networks with different levels of public transport operations. Based on the 3D-vMFD, we analyze and evaluate network performances when the percentage of dedicated bus lanes varies in a city. Simulation results show that when there are more dedicated bus lanes, the performance of cars worsens and the transit performance improves.2
Buchtitel: 2015 IEEE 18th International Conference on Intelligent Transportation Systems (ITSC)
Seiten: 113 - 118
ISBN: 978-1-4673-6595-6, 978-1-4673-6596-3
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Piscataway, N.J.
Publikations-Status: Published
Eventname: 18th International Conference on Intelligent Transportation Systems (ITSC 2015)
Eventdatum: September 15-18, 2015
Ort: Gran Canaria, Spain
Sprache: English
DBID Quelle: FORM-1446036806, SCOPUS-84950293518
DOI: 10.1109/ITSC.2015.27
, Ortigosa, Javier, Zheng, Nan, Menendez, Monica, Geroliminis, Nikolas, 2015 >>
Autor(en): Ortigosa, Javier, Zheng, Nan, Menendez, Monica, Geroliminis, Nikolas
Titel: Analysis of space allocation strategies between buses and cars with the multimodal MFD
Kurzbeschreibung: In this paper we are studying the trade-off of urban space devoted to cars and buses (or trams) in two cities: Zurich and San Francisco. We employ 3D vehicle Macroscopic Fundamental Diagrams (3D- vMFD) which consist of creating the MFDs for vehicles with several public transport frequencies. We analyze the percentage of dedicated bus lanes in a city. When there are more dedicated bus lanes, the car performance worsens and the transit performance improves. The data is generated with two microsimulation models, VISSIM for Zurich, and Aimsum for San Francisco. The ultimate purpose of this paper is to find the optimal percentage of dedicated bus lanes in a city which optimizes the rate of passengers finishing their trips (either by car or by bus). We present this optimization methodology which can help urban planners to find the most efficient share of space for transportation modes in cities.2
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Ascona
Publikations-Status: Accepted
Einordnungen: Traffic operations, MFD, 3D-vMFD, Dedicated lane, Mixed lane, Public Transport
Eventname: 15th Swiss Transport Research Conference (STRC 2015)
Eventdatum: April 15-17, 2015
Ort: Ascona, Switzerland
Sprache: English
Schlüsselwort: Traffic operations, MFD, 3D-vMFD, Dedicated lane, Mixed lane, Public Transport
DBID Quelle: FORM-1432375562
, Ortigosa, Javier, Menendez, Monica, Gayah, Vikash V., 2015 >>
Autor(en): Ortigosa, Javier, Menendez, Monica, Gayah, Vikash V.
Titel: Analysis of the Network Exit Functions for Different Urban Grid Network Configurations
Kurzbeschreibung: Macroscopic network-wide traffic models have been broadly used to study aggregate traffic behavior on urban networks and to design traffic control strategies. However, less attention has been paid to their application in studying street network design. In this paper, we analyze traffic performance on an abstract grid network with different street configurations using the Network Exit Function (NEF)—an aggregate relationship between trip-completion rate and the number of vehicles circulating in a network. This is a topic of recent interest in many cities, especially in the US where city planners are considering street network conversions. In particular, we consider three different configurations: two-way streets (TW), two-way streets with prohibited left turns (TWL), and one-way streets (OW). This work builds on previous studies on this topic by incorporating more realistic traffic dynamics using a micro-simulation software (VISSIM) with Dynamic Traffic Assignment (DTA) enabled to better emulate real drivers behavior. Overall, this work finds that NEFs of TW networks are generally smaller than those of TWL and OW networks due to the reduced capacity offered at intersections. Comparison of TWL and OW networks is more nuanced as traffic performance on these networks depends on route choice. If vehicles are always routed through the path with the shortest travel time, TWL networks offer NEFs with higher trip completion rates. However, if vehicles spread themselves across multiple alternatives, OW networks turn out to provide better results. This occurs because TWL networks offer a better trade-off between distance travelled and capacity at intersections, while OW networks offer more shortest-path routing choices between origin-destination pairs.2
Buchtitel: TRB 94th Annual Meeting Compendium of Papers
Seiten: 15-2886
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Published
Eventname: 94th Annual Meeting of the Transportation Research Board (TRB 2015)
Eventdatum: January 11-15, 2015
Ort: Washington, DC, USA
Sprache: English
DBID Quelle: FORM-1426245974
, Ortigosa, Javier, Gayah, Vikash V., Menendez, Monica, 2015 >>
Autor(en): Ortigosa, Javier, Gayah, Vikash V., Menendez, Monica
Titel: Analysis of Network Exit Functions for Various Urban Grid Network Configurations
Kurzbeschreibung: Macroscopic networkwide traffic models have been used to study aggregate traffic behavior on urban networks and to design traffic control strategies. However, less attention has been given to their application in the study of street network design. This paper uses the network exit function (NEF) to analyze traffic performance on an abstract grid network of various street configurations. The NEF is an aggregate relationship between trip completion rate and the number of vehicles circulating in a network. Street configuration is a topic of interest in many cities, especially in the United States, where city planners are considering street network conversions. Three configurations are addressed here: two-way streets, two-way streets with prohibited left turns (TWL), and one-way streets. This work builds on previous studies by incorporating more realistic traffic dynamics with microsimulation software (VISSIM) with dynamic traffic assignment enabled to emulate better the behavior of real drivers. This work finds that NEFs of two-way networks generally are smaller than those of TWL and one-way networks because of reduced capacity at intersections. Comparison of TWL and one-way networks is more nuanced, as traffic performance on these networks depends on route choice. If vehicles are always routed through the path with the shortest travel time, TWL networks offer NEFs with higher trip completion rates; however, if vehicles spread themselves across multiple alternatives, one-way networks provide better results. TWL networks offer a better trade-off between distance traveled and capacity at intersections, and one-way networks offer more shortest-path routing choices between origin–destination pairs.2
Publiziert in: Transportation Research Record
Band: 2491
Seiten: 12 - 21
ISSN: 0361-1981, 2169-4052
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Washington, DC
Publikations-Status: Published
Sprache: English
DBID Quelle: FORM-1448972342, WOS-000365245600003
DOI: 10.3141/2491-02
Nebis System Nummer: 000024408
, Mühlich, Nicolas, Gayah, Vikash V., Menendez, Monica, 2015 >>
Autor(en): Mühlich, Nicolas, Gayah, Vikash V., Menendez, Monica
Titel: Use of Microsimulation for Examination of Macroscopic Fundamental Diagram Hysteresis Patterns for Hierarchical Urban Street Networks
Kurzbeschreibung: This study used microsimulation to analyze traffic performance on various idealized hierarchical urban street networks. Each network consisted of local streets and arterial streets, which represented the micro- and macrostructure of an urban network, respectively. Arterials were differentiated from local streets through additional green time at intersections and additional travel lanes. An idealized peak period was simulated for completely uniform demand patterns. Observed relationships between average network flow and density—known as the macroscopic fundamental diagram (MFD)—were used to compare the performance of arterial structures. Specifically, the size and shape of hysteresis loops that emerged in the MFD were used, since the networks were found to have more uniform congestion patterns during the onset of congestion than during congestion recovery. The presence of arterials was found to affect significantly the spatial distribution of congestion on the network. Arterials that passed through the congested center of the network and arterials that divided the network resulted in increased congestion inhomogeneity and larger hysteresis loops in the MFD. Arterials placed near the periphery of the network helped to attract vehicles to less-used areas of the network and reduce congestion in the center, which reduced congestion inhomogeneity. Furthermore, limited opportunities to access the arterials also contributed to dense pockets of congestion on nearby streets. For the network and demand conditions studied here, arterial ring roads appeared to distribute congestion more evenly and have had better network performance than arterial grids.2
Publiziert in: Transportation Research Record
Band: 2491
Seiten: 117 - 126
ISSN: 0361-1981, 2169-4052
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Washington, DC
Publikations-Status: Published
Einordnungen: Architektur, Gebaute Umwelt und Umweltgestaltung allgemein|Architecture, Built Environment and Environmental Design, General
Sprache: English
DBID Quelle: FORM-1448972487, WOS-000365245600014
DOI: 10.3141/2491-13
Nebis System Nummer: 000024408
, Jakob, Manuel, Menendez, Monica, Cao, Jin, 2015 >>
Autor(en): Jakob, Manuel, Menendez, Monica, Cao, Jin
Titel: A dynamic macroscopic parking pricing model
Kurzbeschreibung: 2
Publiziert in: SVT Working Paper
Band: 105
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Zürich
Publikations-Status: Unpublished
Sprache: English
DBID Quelle: FORM-1444373883
, He, Haitao, Guler, S. Ilgin, Menendez, Monica, 2015 >>
Autor(en): He, Haitao, Guler, S. Ilgin, Menendez, Monica
Titel: Providing Bus Priority Using Adaptive Pre-signals
Kurzbeschreibung: Bus priority is important in cities to encourage people to use public transport. However, providing a dedicated bus lane is not always feasible. It might not be the most efficient solution either, especially if bottlenecks such as traffic signals exist. This paper examines an alternative strategy to use an additional signal upstream of the main signal (a pre-signal) to provide bus priority at signalized intersections. Its primary purpose is to allow buses to jump the car queues before the intersection while cars can still use all the lanes at the main signal to fully utilize the capacity of the intersection. This paper formulates an online control algorithm to operate an intersection with such pre-signal infrastructure. The control algorithm is developed by determining the best operating strategy for the intersection at each demand level using a micro-simulation model in VISSIM. In a simulation case study, it is observed that compared to using a dedicated bus lane, the congestion upstream of the intersection during peak hours mitigated. Meanwhile, compared to using mixed-use lanes, the average person delay during the off-peak hours is lower and bus priority is provided. Therefore, it is concluded that implementing a pre-signal with the proposed online control algorithm provides a good balance between providing bus priority and sustaining car throughput.2
Buchtitel: TRB 94th Annual Meeting Compendium of Papers
Band: 15-2793
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Published
Eventname: 94th Annual Meeting of the Transportation Research Board (TRB 2015)
Eventdatum: January 11-15, 2015
Ort: Washington, DC, USA
Sprache: English
DBID Quelle: FORM-1423770359
, He, Haitao, Guler, S. Ilgin, Menendez, Monica, 2015 >>
Autor(en): He, Haitao, Guler, S. Ilgin, Menendez, Monica
Titel: Providing Bus Priority Using Adaptive Pre-signals
Kurzbeschreibung: How to dynamically implement different levels of bus priority at intersections while minimizing the negative effects on general traffic using: a dedicated bus lane, a pre-signal, or mixed lanes.2
Seiten: 15-2793
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Published
Eventname: 94th Annual Meeting of the Transportation Research Board (TRB2015)
Eventdatum: January 11-15, 2015
Ort: Washington, DC, USA
Sprache: English
DBID Quelle: FORM-1423071721
, Gómez, Penélope, Menendez, Monica, Mérida-Casermeiro, Enrique, 2015 >>
Autor(en): Gómez, Penélope, Menendez, Monica, Mérida-Casermeiro, Enrique
Titel: Evaluation of trade-offs between two data sources for the accurate estimation of origin–destination matrices
Kurzbeschreibung: In this paper, we evaluate the trade-offs between loop detector data and floating car data (FCD) for the real-time estimation of origin–destination (OD) matrices in small networks. The proposed methodology is based on a bi-level optimisation using fuzzy logic theory. Here we demonstrate that it provides accurate results with low computational cost, while presenting several advantages over other existing algorithms (especially in terms of data requirements, computational complexity, and quality of adjustment). The methodology is illustrated with three examples covering two different locations in the city of Zurich, Switzerland. Results are used to evaluate the trade-offs between loop detector coverage and the penetration rate of FCD, and to determine minimum values for ensuring a given accuracy level on the estimated OD matrices. In general, the resulting error in OD estimation is affected by the data redundancy in the network.2
Publiziert in: Transportmetrica B: Transport Dynamics
Band: 3
Ausgabe: 3
Seiten: 222 - 245
ISSN: 2168-0582, 2168-0566
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Abingdon
Publikations-Status: Published
Einordnungen: Origin–destination (OD) matrix estimation, Floating car data, Loop detectors, Bi-level optimisation, Fuzzy logic
Sprache: English
Schlüsselwort: Origin–destination (OD) matrix estimation, Floating car data, Loop detectors, Bi-level optimisation, Fuzzy logic
DBID Quelle: FORM-1428053886, SCOPUS-84925433189, WOS-000357333400003
DOI: 10.1080/21680566.2015.1025892
, Guler, S. Ilgin, Gayah, Vikash V., Menendez, Monica, 2015 >>
Autor(en): Guler, S. Ilgin, Gayah, Vikash V., Menendez, Monica
Titel: Providing Bus Priority at Signalized Intersections with Single-lane Approaches
Kurzbeschreibung: Signalized intersections often represent a major source of bus delays. One typical strategy to mitigate this problem is to dedicate an existing car lane for bus-use only to minimize the interactions between cars and buses. However, this is physically impossible at approaches where only a single travel lane is available for each direction. To this end, this research explores a novel method to provide priority to buses at signalized intersections with single-lane approaches through the use of additional signals in a way that (nearly) eliminates bus delays while minimizing the negative impacts imparted to cars. Using these signals, the bus can jump a portion of the car queue using the travel lane in the opposite direction. This paper theoretically quantifies the delay savings buses can achieve, and the negative impacts imparted onto cars when this pre-signal strategy is applied. The negative impacts are measured as the additional car delays experienced when the intersection signal is under-saturated, and the reduction in car-discharge capacity when the intersection signal is over-saturated. In the under- saturated case, the results show that moderate average bus delay savings (~5-7 seconds per vehicle) are achieved if the pre-signal is always in operation; and these results decrease the total system-wide delay (measured in person-hours) only if bus occupancies are very high. However, if the pre-signal operation is targeted to only provide priority to the buses that would benefit the most, significant bus delay savings can be achieved (delay benefits to buses which receive priority are about doubled) while also reducing the system-wide delay, even if the ratio of bus to car occupancy is relatively modest (greater than about 20). In the over-saturated case, bus delay savings can be much more significant than under-saturated cases (greater than 30 seconds per bus), and this delay saving can increase further for longer block lengths (greater than 100 m). However, the capacity of the intersection decreases by up to 25% during each cycle in which a bus arrives to the intersection. Simulation tests confirmed that the general trends and magnitudes of bus delay savings and negative impacts to cars hold for more realistic behaviors. The overall benefits are slightly smaller in the simulations, but nevertheless the strategy seems promising as a bus priority strategy at intersections with single-lane approaches in the field.2
Publiziert in: Transportation Research Procedia
Band: 9
Ausgabe: 2015
Seiten: 225 - 245
ISSN: 2352-1465
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Amsterdam
Publikations-Status: Published
Einordnungen: Bus priority, Pre-signal, Signalized intersection, Single-lane approaches
Sprache: English
Schlüsselwort: Bus priority, Pre-signal, Signalized intersection, Single-lane approaches
DBID Quelle: FORM-1438773011
DOI: 10.1016/j.trpro.2015.07.013
Nebis System Nummer: 010514383
, Cao, Jin, Menendez, Monica, Nikias, Vasileios, 2015 >>
Autor(en): Cao, Jin, Menendez, Monica, Nikias, Vasileios
Titel: The effects of on-street parking on the service rate of nearby intersections
Kurzbeschreibung: An on-street parking maneuver can often start a temporary bottleneck, leading to additional delay endured by the following vehicl es. If the maneuver occurs near a signalized intersection, the service rate of the intersection might be reduced. In this paper, a model is built to analyze the effects of parking maneuvers on the intersection service rate. Based on the hydrodynamic theory of traf?c ?ow, the perturbation caused by the parking mane uver is analyzed. Using dimension al analysis, we illustrate the relation between the background conditions, the distance from the parking area to the intersection, and the intersection service rate. Based on this relation, one can compute the service rate reduction caused by existing on-street parking areas. A minimum distance between the parking are a and the intersection to avoid such reduction can be accordingly found. Numerical examples based on empirical data from the city of Zurich, Switzerland, are provided to illustrate the practical applications. Although the analysis is based on streets with a single lane per direction, the ?ndings can provide some insights regarding different situations. We hope such ?ndings can be used as a basis for developing on-street parking design guideline s.2
Publiziert in: Journal of Advanced Transportation
ISSN: 0197-6729, 2042-3195
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Durham, NC
Publikations-Status: Published
Sprache: English
DBID Quelle: FORM-1395922787
DOI: 10.1002/atr.1329
Nebis System Nummer: 000006890
, Cao, Jin, Menendez, Monica, 2015 >>
Autor(en): Cao, Jin, Menendez, Monica
Titel: Generalized effects of on-street parking maneuvers on the performance of nearby signalized intersections
Kurzbeschreibung: 2
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Washington, DC
Publikations-Status: Published
Eventname: 94th Annual Meeting of the Transportation Research Board, TRB2015
Eventdatum: January 11-15, 2015
Ort: Washington, DC, USA
Sprache: English
DBID Quelle: FORM-1423241415
, Cao, Jin, Menendez, Monica, 2015 >>
Autor(en): Cao, Jin, Menendez, Monica
Titel: Generalized effects of on-street parking maneuvers on the performance of nearby signalized intersections
Kurzbeschreibung: An on-street parking maneuver can often start a temporary bottleneck, leading to additional delay endured by the following vehicles. When the maneuver occurs at a close distance upstream a signalized intersection, the scope of the impact can be magnified. In this case, the intersection might be starved for traffic due to the parking maneuver, so a portion of the intersection capacity is wasted. In this paper, we estimate the service rate reduction due to the delay caused by an upstream parking maneuver at different locations and provide suggestions to avoid such reduction. Based on the hydrodynamic theory of traffic flow, the perturbation caused by the parking maneuver is calculated. Using dimensional analysis, we analyze the relation between the background conditions (i.e, traffic volume, traffic saturation condition, signal control settings, etc.), the time/location of the parking maneuver, and the service rate reduction at the intersection. Combined with a previous study, the analysis on the effects of parking maneuvers at different locations nearby a signalized intersection is now complete (both upstream and downstream parking maneuvers are included). The results show that, generally, for an undersaturated intersection, parking downstream of the intersection causes less negative effects on service rate than parking upstream. However, for an oversaturated intersection, parking at a close distance downstream of the intersection might reduce the service rate significantly. We hope the conclusions can be used to guide parking planning/management under different background conditions and to assist the development of parking regulations (such as dynamic parking supply according to real-time traffic conditions).2
Seiten: 15-1557
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Washington, DC
Publikations-Status: Published
Eventname: 94th Annual Meeting of the Transportation Research Board, TRB2015
Eventdatum: January 11-15, 2015
Ort: Washington, DC, USA
Sprache: English
DBID Quelle: FORM-1423240468
, Cao, Jin, Menendez, Monica, 2015 >>
Autor(en): Cao, Jin, Menendez, Monica
Titel: Cruising for parking: causes, effects, and control strategies
Kurzbeschreibung: 2
Publiziert in: SVT Working Papers
Band: 103
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Zürich
Sprache: English
DBID Quelle: FORM-1437811881
, Cao, Jin, Menendez, Monica, 2015 >>
Autor(en): Cao, Jin, Menendez, Monica
Titel: Analysis on parking policies considering the effects of searching-for-parking on the general traffic performance
Kurzbeschreibung: 2
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Ascona
Publikations-Status: Unpublished
Eventname: 15th Swiss Transport Research Conference (STRC 2015)
Eventdatum: 15-17 April 2015
Ort: Ascona, Switzerland
Sprache: English
DBID Quelle: FORM-1432370620
, Cao, Jin, Menendez, Monica, 2015 >>
Autor(en): Cao, Jin, Menendez, Monica
Titel: A parking-state-based transition matrix of traffic on urban networks
Kurzbeschreibung: The urban parking and the urban traffic systems are essential components of the overall urban transportation structure. The short- term interactions between these two systems can be highly significant and influential to their individual performance. The urban parking system, for example, can affect the searching-for-parking traffic, influencing not only overall travel speeds in the network (traffic performance), but also total driven distance (environmental conditions). In turn, the traffic performance can also affect the time drivers spend searching for parking, and ultimately, parking usage. In this study, we propose a methodology to model macroscopically such interactions and evaluate their effects on urban congestion.

The model is built on a transition matrix describing how, over time, vehicles in an urban area transition from one parking-related state to another. With this model it is possible to estimate, based on the traffic and parking demand as well as the parking supply, the amount of vehicles searching for parking, the amount of vehicles driving on the network but not searching for parking, and the amount of vehicles parked at any given time. More importantly, it is also possible to estimate the total (or average) time spent and distance driven within each of these states. Based on that, the model can be used to design and evaluate different parking policies, to improve (or optimize) the performance of both systems.

A simple numerical example is provided to show possible applications of this type. Parking policies such as increasing parking supply or shortening the maximum parking duration allowed (i.e., time controls) are tested, and their effects on traffic are estimated. The preliminary results show that time control policies can alleviate the parking-caused traffic issues without the need for providing additional parking facilities. Results also show that parking policies that intend to reduce traffic delay may, at the same time, increase the driven distance and cause negative externalities. Hence, caution must be exercised and multiple traffic metrics should be evaluated before selecting these policies.

Overall, this paper shows how a parking-state-based transition matrix, despite its simplicity, can be used to efficiently evaluate the urban traffic and parking systems macroscopically. The proposed model can be used to estimate both, how parking availability can affect traffic performance (e.g., average time searching for parking, number of cars searching for parking); and how different traffic conditions (e.g., travel speed, density in the system) can affect drivers ability to find parking. Moreover, the proposed model can be used to study multiple strategies or scenarios for traffic operations and control, transportation planning, land use planning, or parking management and operations.2
Publiziert in: Transportation Research Procedia
Band: 7
Seiten: 149 - 169
ISSN: 2352-1465
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Amsterdam
Publikations-Status: Published
Einordnungen: Macroscopic parking model, Traffic congestion, Parking-related traffic state, Cruising-for-parking, Transition matrix of traffic
Eventname: 21st International Symposium on Transportation and Traffic Theory
Eventdatum: August 5-7, 2015
Ort: Kobe, Japan
Sprache: English
Schlüsselwort: Macroscopic parking model, Traffic congestion, Parking-related traffic state, Cruising-for-parking, Transition matrix of traffic
DBID Quelle: FORM-1423936712
DOI: 10.1016/j.trpro.2015.06.009
Nebis System Nummer: 010514383
, Arnet, Kathrin, Guler, S. Ilgin, Menendez, Monica, 2015 >>
Autor(en): Arnet, Kathrin, Guler, S. Ilgin, Menendez, Monica
Titel: Effects of Multimodal Operations on Urban Roadways
Kurzbeschreibung: Public transportation (e.g., buses) can improve the efficiency of urban transportation systems by carrying more people using less amount of space. Hence, to prioritize this mode a commonly used solution is to dedicate a lane for bus use only. However, how the capacity of the system (cars and buses) would change if a dedicated bus lane were used instead of completely mixed-used lanes is not clear yet. Even if the capacity of the dedicated bus lane were not fully utilized due to low bus flows, this strategy could still increase the car capacity in the remaining lanes. The bus travelling on a separate lane would eliminate conflicting bus maneuvers, and the reduced number of lanes available for car traffic could also reduce the number of lane changes. Both of these factors could increase the capacity of the remaining car lanes. This paper empirically analyzes the differences in car capacity between: i) a mixed-use scenario without the influence of buses and a dedicated-lane scenario; and ii) a mixed-use lane scenario with and without buses. The results show that with mixed-use lanes the car-capacity per lane remains the same as compared to having one lane dedicated for bus-use only, implying that at this specific urban intersection lane changes do not disrupt the traffic flow. However, it is observed that in mixed-use conditions, the presence of a bus in the traffic flow can reduce the capacity by 20% due to the space in front of the bus not being fully utilized by cars, and the slower travel speed of the bus affecting the cars behind it. Finally based on these findings a simple analysis is carried out to compare the passenger-delay at urban bottlenecks, specifically signalized intersections with a mixed-use lane scenario vs. a dedicated bus lane scenario. It is shown that the passenger-delay can be reduced with the use of dedicated bus lanes if the bus occupancies are relatively high or if the car demand is low.2
Buchtitel: TRB 94th Annual Meeting Compendium of Papers
Seiten: 15-0198
Publikationsdatum / Empfangsdatum: 2015-01-01
Publikations-Status: Published
Eventname: 94th Annual Meeting of the Transportation Research Board (TRB2015)
Eventdatum: January 11-15, 2015
Ort: Washington, DC, USA
Sprache: English
DBID Quelle: FORM-1422898116
, Sasidharan, Lekshmi, Menendez, Monica, 2014 >>
Autor(en): Sasidharan, Lekshmi, Menendez, Monica
Titel: Partial Proportional Odds Model
Untertitel: An Alternate Choice for Analyzing Pedestrian Crash Injury Severities
Kurzbeschreibung: The conventional methods for crash injury severity analyses include either treating the severity data as ordered (e.g. ordered logit/probit models) or non-ordered (e.g. multinomial models). The ordered models require the data to meet proportional odds assumption, according to which the predictors can only have the same effect on different levels of the dependent variable, which is often not the case with crash injury severities. On the other hand, non-ordered analyses completely ignore the inherent hierarchical nature of crash injury severities. Therefore, treating the crash severity data as either ordered or non-ordered results in violating some of the key principles. To address these concerns, this paper explores the application of a partial proportional odds (PPO) model to bridge the gap between ordered and non-ordered severity modeling frameworks. The PPO model allows the covariates that meet the proportional odds assumption to affect different crash severity levels with the same magnitude; whereas the covariates that do not meet the proportional odds assumption can have different effects on different severity levels. This study is based on a five-year (2008–2012) national pedestrian safety dataset for Switzerland. A comparison between the application of PPO models, ordered logit models, and multinomial logit models for pedestrian injury severity evaluation is also included here. The study shows that PPO models outperform the other models considered based on different evaluation criteria. Hence, it is a viable method for analyzing pedestrian crash injury severities.2
Publiziert in: Accident analysis and prevention
Band: 72
Seiten: 330 - 340
ISSN: 0001-4575
Publikationsdatum / Empfangsdatum: 2014-11-01
Publikations-Status: Amsterdam
Publikations-Status: Published
Einordnungen: Crash severity, Partial proportional odds model, Ordered logit model, Multinomial logit model, Pedestrian, Comparison
Sprache: English
Schlüsselwort: Crash severity, Partial proportional odds model, Ordered logit model, Multinomial logit model, Pedestrian, Comparison
DBID Quelle: FORM-1407825418, WOS-000343843700034
DOI: 10.1016/j.aap.2014.07.025
Nebis System Nummer: 000041481
, Ortigosa, Javier, Menendez, Monica, Tapia, Hector, 2014 >>
Autor(en): Ortigosa, Javier, Menendez, Monica, Tapia, Hector
Titel: Study on the number and location of measurement points for an MFD perimeter control scheme
Untertitel: A case study of Zurich
Kurzbeschreibung: The goal of this paper is to evaluate the data requirements for a possible implementation of a macroscopic fundamental diagram (MFD) control scheme in an urban area. Particularly, we have studied the accuracy of MFDs created using only a percentage of the links (i.e., streets). This is especially useful because monitoring resources are often scarce, and most cities do not have access to the large amount of information that is typically associated with the construction of an MFD. We evaluated several strategies that cities typically use to place fixed monitoring devices (e.g., loop detectors), and compared them with a quasi-optimal way to choose the links. The results show that independently of the strategy used for link selection, a minimum of 25 % of network coverage, according to our accuracy methodology, ensures an average error in density ratios below 15 percentage points (ppts). Based on the particular case of the city of Zurich, we also analyzed the feasibility of implementing an MFD control scheme with the links that are currently monitored. Results are very encouraging, showing an average error below 9 ppts. Although all results were obtained with a VISSIM microsimulation model of the inner city of Zurich, we believe the knowledge and methodology presented here can be transferred to other urban areas. In fact, we are hopeful that this research can contribute to making the implementation of an MFD control scheme feasible for many cities.2
Publiziert in: EURO Journal on Transportation and Logistics
Band: 3
Ausgabe: 3-4
Seiten: 245 - 266
ISSN: 2192-4376, 2192-4384
Publikationsdatum / Empfangsdatum: 2014-10-01
Publikations-Status: Berlin ; Heidelberg
Publikations-Status: Published
Einordnungen: Macroscopic fundamental diagram, Network fundamental diagram, Urban traffic, Perimeter control implementation, Zürich, Traffic measurements, Traffic monitoring
Sprache: English
Schlüsselwort: Macroscopic fundamental diagram, Network fundamental diagram, Urban traffic, Perimeter control implementation, Zürich, Traffic measurements, Traffic monitoring
DBID Quelle: FORM-1378475229, FORM-1354367191
DOI: 10.1007/s13676-013-0034-0
, Menendez, Monica, 2014 >>
Autor(en): Menendez, Monica
Titel: Area speed limits vs. capacity in urban networks
Kurzbeschreibung: 2
Publikationsdatum / Empfangsdatum: 2014-09-16
Publikations-Status: Published
Sprache: English
DBID Quelle: FORM-1422645778
, Menendez, Monica, 2014 >>
Autor(en): Menendez, Monica
Titel: Intermodal capacity of links, segments, and networks
Kurzbeschreibung: 2
Publikationsdatum / Empfangsdatum: 2014-09-01
Publikations-Status: Unpublished
Eventname: SVI Research Symposium
Eventdatum: September 18, 2014
Ort: Olten, Switzerland
Sprache: English
DBID Quelle: FORM-1422645634
, Ortigosa, Javier, Thomann, Sylvie, Ge, Qiao, Menendez, Monica, 2014 >>
Autor(en): Ortigosa, Javier, Thomann, Sylvie, Ge, Qiao, Menendez, Monica
Titel: Dynamic properties of grid urban networks
Kurzbeschreibung: Urban grid networks might present different ways to structure streets and consequently, traffic, might be accommodated differently. In the present paper, we analyze three grid configurations: two-way streets, two-way streets with prohibited left turns, and one-way streets. We simulate traffic in them with the micro simulation software VISSIM and we distribute trips employing the dynamic traffic assignment integrated in it. In this way, we are able to analyze the dynamic behavior of traffic. Typically, in static simulations, oversaturated links or intersections have really large delays but these delays, contrary to what happens in reality, do not affect other links. We are interested in understanding which configuration is more resilient to the propagation of congestion, and this cannot be seen when employing static models. In addition, the static simulations provide macroscopic indicators such as the total travel time or the total travel distance. However, the dynamic perspective provides a new set of indicators to evaluate our networks, and we are especially interested in using the Macroscopic Fundamental Diagram (MFD) as one of them. The MFD is a traffic monitoring scheme that determines the upper bound of network traffic states relating trip production rate and density of trips. Our goal is to generate MFDs in the different networks and to employ it as indicators of the network performance. Depending on the MFD shape, networks might have different properties when dealing with traffic. In this paper, we discuss this issue by comparing the three different urban grid configurations.2
Publikationsdatum / Empfangsdatum: 2014-05-01
Publikations-Status: Monte Veritá, Ascona, Switzerland
Publikations-Status: Published
Einordnungen: Traffic operations, MFD, Network modeling, DTA, Grid, Urban planning
Eventname: 14th Swiss Transport Research Conference (STRC 2014)
Eventdatum: May 14-16, 2014
Ort: Ascona, Switzerland
Sprache: English
Schlüsselwort: Traffic operations, MFD, Network modeling, DTA, Grid, Urban planning
DBID Quelle: FORM-1400079292
, Theodoridou, Sofia, Guler, S. Ilgin, Menendez, Monica, 2014 >>
Autor(en): Theodoridou, Sofia, Guler, S. Ilgin, Menendez, Monica
Titel: An analytical approach for modelling tolled bus lanes
Kurzbeschreibung: High-occupancy vehicle (HOV) and bus lanes have been widely implemented in several countries as a measure to reduce highway congestion, or provide bus priority, in urban or suburban transportation networks. While general use lanes can be congested, if flows in bus or HOV lanes are low, these lanes can be severely underutilized. If ordinary vehicles, such as cars, are allowed in the bus lane at certain rates and in exchange of some toll, however, an optimized operation for all lanes could be achieved. Hence, the aim of this paper is to provide a generalized solution regarding the allowance rate of cars in the bus lane, as well as the toll rates that should be applied.2
Publikationsdatum / Empfangsdatum: 2014-04-01
Publikations-Status: Ascona
Publikations-Status: Published
Einordnungen: Bus lanes, Traffic operations, Tolled lanes
Eventname: 14th Swiss Transport Research Conference (STRC 2014)
Eventdatum: May 14-16, 2014
Ort: Monte Verità, Ascona, Switzerland
Sprache: English
Schlüsselwort: Bus lanes, Traffic operations, Tolled lanes
DBID Quelle: FORM-1400083177
, Ge, Qiao, Ortigosa, Javier, Menendez, Monica, 2014 >>
Autor(en): Ge, Qiao, Ortigosa, Javier, Menendez, Monica
Titel: Traffic demand pattern generation for a grid network based on experiment design
Kurzbeschreibung: In this paper, we present a preliminary approach for generating different traffic demand patterns to analyze the traffic performance of a grid network. The proposed methodology is based on the sampling strategy proposed in (Ge and Menendez, 2013), and combined with ideas from research on experiment design. The proposed algorithm is illustrated using an abstract grid network with bidirectional streets. The purpose of this paper is to demonstrate how does this algorithm work for investigating the relationship between different spatial distributions of the demand (i.e., geographical position where the demand is generated/attracted) and the traffic performances. In this study, we have tried multiple magnitude of the total demand (i.e., quantity of the demand) in the network, but no variation of the temporal distribution (i.e., time when the demand is generated) is considered. Based on the evaluation of the analysis results, we are able to conclude the best and the worst traffic demand conditions in terms of traffic performance for the given grid network.2
Publikationsdatum / Empfangsdatum: 2014-04-01
Publikations-Status: Ascona
Publikations-Status: Published
Einordnungen: Traffic demand pattern, Network, Experiment design, Traffic performance
Eventname: 14th Swiss Transport Research Conference (STRC 2014)
Eventdatum: May 14-16, 2014
Ort: Monte Verità, Ascona, Switzerland
Sprache: English
Schlüsselwort: Traffic demand pattern, Network, Experiment design, Traffic performance
DBID Quelle: FORM-1400078784
, Theodoridou, Sofia, Guler, S. Ilgin, Menendez, Monica, 2014 >>
Autor(en): Theodoridou, Sofia, Guler, S. Ilgin, Menendez, Monica
Titel: An Analytical Approach for Modeling Tolled Bus Lanes
Kurzbeschreibung: 2
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Unpublished
Eventname: 11th International Congress on Advances in Civil Engineering (ACE 2014)
Eventdatum: October 21-25, 2014
Ort: Istanbul, Turkey
Sprache: English
DBID Quelle: FORM-1420729416
, Stempfel, Julie, Guler, S. Ilgin, Menendez, Monica, Brucks, Wernher, 2014 >>
Autor(en): Stempfel, Julie, Guler, S. Ilgin, Menendez, Monica, Brucks, Wernher
Titel: Effects of traffic conditions on safety of urban networks
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Published
Eventname: 93rd Annual Meeting of the Transportation Research Board (TRB 2014)
Eventdatum: January 12-16, 2014
Ort: Washington, DC, USA
Sprache: English
DBID Quelle: FORM-1393332738
, Sasidharan, Lekshmi, Menendez, Monica, 2014 >>
Autor(en): Sasidharan, Lekshmi, Menendez, Monica
Titel: Partial Proportional Odds Model - A Better Choice for Analyzing Pedestrian Crash Injury Severities
Kurzbeschreibung: The conventional methods for crash injury severity analyses include either treating the severity data as ordered (e.g. ordered logit/probit models) or non-ordered (e.g. multinomial models). The ordered models require the data to meet proportional odds assumption, according to which the predictors can have only the same effect on different levels of the dependent variable, which is often not the case with crash injury severities. On the other hand, non-ordered analyses completely ignore the inherent hierarchical nature of crash injury severities. Therefore, treating the crash severity data as either ordered or non-ordered results in violating some of the key principles. To address these concerns, this paper explores the application of a partial proportional odds (PPO) model to bridge the gap between ordered and non-ordered severity modeling frameworks. The PPO model allows the covariates that meet the proportional odds assumption to affect different crash severity levels with the same magnitude; whereas the covariates that do not meet the proportional odds assumption can have different effects on different severity levels independently. This study is based on the five year (2008-2012) national pedestrian safety dataset for Switzerland. A comparison between the application of PPO models, ordered logit models, and multinomial logit models for pedestrian injury severity evaluation is also included in the study. The analysis shows that PPO models outperform ordered logit and multinomial logit models based on different evaluation criteria used in the paper.
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Zurich
Publikations-Status: Published
Sprache: English
DBID Quelle: FORM-1395927281
, Sasidharan, Lekshmi, Menendez, Monica, 2014 >>
Autor(en): Sasidharan, Lekshmi, Menendez, Monica
Titel: Beneficial and Detrimental Factors Influencing Pedestrian Crash Injury Severities in Switzerland Using Partial Proportional Odds Model
Kurzbeschreibung: Problem: According to the Swiss Microcensus, Switzerland is a place where people choose to walk more than 40% of their daily trip time, resulting in a high pedestrian crash to total crash ratio when compared to many other developed countries. Furthermore, the high number of old and young pedestrians as well as the large number of pedestrian crashes with higher levels of severity makes the pedestrian crash analysis for Switzerland very important. However, to the best of author's knowledge, no scientific research has been conducted on evaluating the role of critical factors influencing the severity level of pedestrian crashes in the country. This study aims to identify the important crash contributing factors that alleviate and aggravate the injury severity levels of pedestrian-vehicle crashes in Switzerland. Method: This study employs a Partial Proportional Odds model (Generalized ordered logit model) to analyze pedestrian crash injury severities in Switzerland, based on the five-year (2008-2012) pedestrian safety data. The study also focuses on a separate analysis of influential factors for crashes involving old and young pedestrians, who are more vulnerable to higher levels of injury severity when involved in a crash . Results: The results of the study indicate that old pedestrians and young pedestrians are more prone to serious injuries when involved in crashes. Irrespective of age, dark unlighted areas, sight obstructions, mid-block crossings and heavy vehicles were found to adversely affect the injury severity levels of pedestrians. On the other hand, German speaking areas, low speed urban areas, and flat road sections were found to positively influence pedestrian injury severities in Switzerland. Practical Applications: Discussion on the effects of pedestrian, driver and infrastructure characteristics, and roadway crossing behavior of pedestrians in different age groups will help to improve traffic safety related policies in Switzerland.
Publiziert in: SVT Working Paper
Band: 71
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Zürich
Publikations-Status: Published
Einordnungen: Pedestrian, Injury, Severity, Ordered logit, Partial proportional odds, Generalized ordered logit, Proportional odds assumption, Parallel lines assumption, Switzerland
Sprache: English
Schlüsselwort: Pedestrian, Injury, Severity, Ordered logit, Partial proportional odds, Generalized ordered logit, Proportional odds assumption, Parallel lines assumption, Switzerland
DBID Quelle: FORM-1406983855
, Ortigosa, Javier, Menendez, Monica, 2014 >>
Autor(en): Ortigosa, Javier, Menendez, Monica
Titel: Traffic performance on quasi-grid urban structures
Kurzbeschreibung: Cities across the world are starting to recover space, previously devoted to cars, for other uses. The main purpose of this paper is to better understand the removal of space in urban settings and to provide some analytical results showing that it is possible to remove streets from a city without worsening traffic excessively. We have created an abstract grid network composed of 100 nodes and bidirectional streets. A simple demand model is applied to load the network effectively, emulating a dense urban environment. We have developed a static traffic assignment model using the Frank–Wolfe algorithm. The link removal strategies seek to represent city planning policies aiming at recovering space for other activities. Links are removed following three different strategies: in a total random manner, focusing on the center of the grid, and focusing on the perimeter of the grid. Up to 30% of the total links of the full grid are removed. The results indicate that a certain number of links can be removed without affecting traffic considerably. As it will be seen, this magnitude is very dependent on the link removal strategy. Our case covers a homogeneous grid with uniform demand where the central links carry higher flow. For that, the peripheral removal allows the highest rate of link removal, whereas the central removal is the most restrictive strategy. The restriction of capacity at intersections is the main bottleneck of the system when links are removed, driving most of the increase in delays. Under these conditions, the peripheral removal retains a higher connectivity in the center, allowing a better distribution of flows.
Publiziert in: Cities
Band: 36
Ausgabe: 2014
Seiten: 18 - 27
ISSN: 0264-2751
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Oxford
Publikations-Status: Published
Einordnungen: Raumordnung, Städtebau, Landschaftsarchitektur|Spatial and Urban Planning, Landscape Architecture, Link removal, Urban pattern, Traffic performance, Grid
Sprache: English
Schlüsselwort: Link removal, Urban pattern, Traffic performance, Grid
DBID Quelle: FORM-1378474921, SCOPUS-84884542922, WOS-000329386100003
DOI: 10.1016/j.cities.2013.08.006
Nebis System Nummer: 001755650
, Ortigosa, Javier, Menendez, Monica, 2014 >>
Autor(en): Ortigosa, Javier, Menendez, Monica
Titel: Analyzing the shape of the Macroscopic Fundamental Diagram on grid urban networks for urban planning purposes
Kurzbeschreibung: In this paper we emulate the dynamics of traffic in three urban grid networks: two way streets, one way streets, and two way streets with prohibited left turns. We pay particular attention to the shape (e.g. height, width, area) of the Macroscopic Fundamental Diagrams (MFD) obtained. We believe that the characteristics of the MFD can also reveal properties of the network to support urban planning and land use policies in urban areas. Hence, we analyze in detail this relationship between urban form and MFD shape and we discuss which should be the optimal MFD shape in an urban network.2
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Barcelona
Publikations-Status: Published
Einordnungen: Transportation, Public Tranport and Traffic, Operations Management
Eventname: 20th Conference of the International Federation of Operational Research Societies (IFORS 2014)
Eventdatum: July 13-18, 2014
Ort: Barcelona, Spain
Sprache: English
Schlüsselwort: Transportation, Public Tranport and Traffic, Operations Management
DBID Quelle: FORM-1420731726
, Ortigosa, Javier, Gayah, Vikash V., Menendez, Monica, 2014 >>
Autor(en): Ortigosa, Javier, Gayah, Vikash V., Menendez, Monica
Titel: Comparison of traffic performance in finite grids with different configurations: analytical versus simulated approach
Kurzbeschreibung: 2
Seiten: 14-3962_C
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: S.l.
Publikations-Status: Published
Eventname: 93rd Annual Meeting of the Transportation Research Board
Eventdatum: January 12-16, 2014
Ort: Washington, DC, USA
Sprache: English
DBID Quelle: FORM-1378474235
, Ortigosa, Javier, Gayah, Vikash V., Menendez, Monica, 2014 >>
Autor(en): Ortigosa, Javier, Gayah, Vikash V., Menendez, Monica
Titel: Analysis of one-way and two-way street configurations on urban grid networks
Kurzbeschreibung: The design of urban street networks is a subject of much controversy because there is no consensus on the best way to organize streets to maximize mobility. Debates between one-way and two-way street networks have existed since cars were introduced into urban environments and are still ongoing. In this paper, we provide additional insights on this issue by analyzing traffic behavior on three different street configurations: one-way streets, two-way streets, and two-way streets with prohibited left turns. The outcomes of this paper will furnish urban planners and policy makers with a better understanding of the mobility provided by each of these types of urban street network layouts.

This study is focused on abstract finite grids operating in both uncongested and congested conditions. Analytical formulations are created and used to compare the three network types under low demand scenarios when the network is uncongested. These formulations rely on a fixed traffic assignment scheme in which drivers are assumed to minimize their overall travel distance and number of turning maneuvers. They are used to reveal general insights. In addition, simulation techniques are employed with a static traffic assignment algorithm to examine the behavior of networks under more realistic congested situations.

In general, the study reveals that two-way networks provide the shortest distance traveled and result in more uniform congestion patterns due to route redundancy. However, they are severely penalized by restrictions in capacity at the intersections due to more complicated phasing schemes, which leads to higher average travel times when the network is large, has short links, or is lightly congested. One- way networks offer the longest travel distances but have intersections with very high capacity. They perform better when the network is very large or links are very short. Finally, two-way networks with prohibited left turns provide the best compromise between distance traveled and intersection capacity, which makes them suitable for many different scenarios with low and medium congestion. Their main weakness is that they suffer from inhomogeneous congestion patterns caused by a lack of route redundancy. This could lead to very large travel times when the network is very congested.2
Publiziert in: SVT Working Paper
Band: 75
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Zürich
Publikations-Status: Published
Einordnungen: Urban traffic, Urban network design, Grid, One-way streets, Two-way streets, Prohibited left turns
Sprache: English
Schlüsselwort: Urban traffic, Urban network design, Grid, One-way streets, Two-way streets, Prohibited left turns
DBID Quelle: FORM-1412356733
, Ortigosa, Javier, Gayah, Vikash, Menendez, Monica, 2014 >>
Autor(en): Ortigosa, Javier, Gayah, Vikash, Menendez, Monica
Titel: Comparison of Traffic Performance in Finite Grids with Different Configurations
Untertitel: Analytical Versus Simulated Approach
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Published
Eventname: 93rd Annual Meeting of the Transportation Research Board (TRB 2014)
Eventdatum: January 12-16, 2014
Ort: Washington, DC, USA
Sprache: English
DBID Quelle: FORM-1393332407
, Mühlich, Nicolas, Gayah, Vikash V., Menendez, Monica, 2014 >>
Autor(en): Mühlich, Nicolas, Gayah, Vikash V., Menendez, Monica
Titel: An Examination of MFD Hysteresis Patterns for Hierarchical Urban Street Networks Using Micro-Simulation
Kurzbeschreibung: This study analyzes traffic performance on various idealized hierarchical urban street networks using micro-simulation. Each network consists of local streets and arterial streets, which represent the micro- and macro-structure of an urban network, respectively. Arterials were differentiated from local street s through additional green time at intersections and additional travel lanes. An idealized peak period is si mulated under completely uniform demand patterns. Observed relationships between average network flow and de nsity—known more commonly as the Macroscopic Fundamental Diagram (or MFD) —are used to compare the performance of different arterial structures. Spec ifically, the size and shape of hysteresis loops that emerge in the MFD are used, since the networks were found to have more uniform congestion patterns during the onset of congestion than during congestion re covery. The presence of arterials was found to significantly impact the spatial distribution of congestion on the networ k. Arterials that pass through the congested center of th e network and arterials that di vide the network resulted in increased congestion inhomogeneity and larger hys teresis loops in the MFD. Arterials placed near the periphery of the network helped to attract vehicles to lesser used areas of the network and reduce congestion in the center, both of wh ich served to reduce congestion inhomogeneity. Furthermore, limited opportunities to access the arte rials also contribute to dense pockets of congestion on nearby streets. For the network and demand conditions studied here, arterial ring roads appear to distribute congestion more even ly and have better network performance than arterial grids.2
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Published
Eventname: 94th Annual Meeting of the Transportation Research Board
Eventdatum: January 11-15, 2015
Ort: Washington, D.C., USA
Sprache: English
DBID Quelle: FORM-1416157298
, Menendez, Monica, Guler, S. Ilgin, Puffe, Enrico, 2014 >>
Autor(en): Menendez, Monica, Guler, S. Ilgin, Puffe, Enrico
Titel: Traffic flow at uncontrolled urban intersections with attention to different modes of traffic: Determination of representative standard values and interrelations
Kurzbeschreibung: Das in VSS-Norm SN 640 022 enthaltene Schätzverfahren zur Bemessung von Knoten ohne Lichtsignalanlagen berücksichtigt nur Konfliktsituationen zwischen Motorfahrzeugen. Da in diesem Verfahren die Einflüsse des öffentlichen Verkehrs sowie der Fussgänger und Velofahrer nicht berücksichtigt sind, kann diese Norm für städtische Verhältnisse nicht angewendet werden. Im Forschungsauftrag VSS 2008/301 wurde ein analytisches Verfahren entwickelt, welches die Berücksichtigung verschiedener Verkehrsarten an ungesteuerten Knoten ermöglicht. Die Methodik des neuen Schätzverfahrens basiert auf Sättigungswerten der vortrittsberechtigten und vortrittsbelasteten Motorfahrzeuge sowie auf den Zusammenhängen zwischen Sättigung und Verkehrsstärke an Konfliktpunkten. Diese wurden aufgrund von kurzzeitigen Zählungen in der Stadt Zürich geschätzt. Bei den in VSS 2008/301 angegebenen Sättigungswerten für öffentliche Verkehrsmittel, Fussgänger und Velofahrer handelt es sich um Erfahrungswerte. Diese Werte sind in der geplanten Untersuchung zu überprüfen. Zu diesem Zweck sind mittels empirischer Untersuchungen an Knoten mit Referenzcharakter die für schweizerische Verhältnisse repräsentativen Richtwerte zu ermitteln. Dabei sind Verhältnisse in verschieden grossen Städten zu berücksichtigen. Bei den Zusammenhängen zwischen Verkehrsstärke und Sättigung stehen die Wechselwirkungen im Vortrittsverhalten zwischen vortrittsberechtigten und vortrittsbelasteten Verkehrsteilnehmern am Konfliktpunkt im Vordergrund. Dazu sind entsprechende Schwellenwerte abzuleiten. Die Richtwerte der maximalen Sättigung vortrittsberechtigter und vortrittsbelasteter Fussgänger, Velofahrer, Trams und Busse können zudem aufgrund der Ergebnisse in den laufenden Forschungsarbeiten VSS 2007/306 und VSS 2007/305 verifiziert werden. Aufgrund der neuen Erkenntnisse ist ein Normentwurf zu erarbeiten.

The estimation method contained in VSS standard SN 640 022 to the assessment of uncontrolled intersections takes into account only conflict situations between motor vehicles. Since in this method the influences of the public transport as well as the pedestrians and bicycles are not considered, this standard cannot be used for urban conditions. An analytical method which considers the different traffic types at uncontrolled intersections was developed in the research project VSS 2008/301. The methodology of the new estimation method is based on saturation values of the motor vehicles with the right of way and those that have to give way as well as on the coherences between saturation and traffic volume at conflict areas. These were valued due to short-time measurements in the city of Zurich. The saturation values regarding to the public transport, pedestrians and bicycles are based on experience. These values have to be checked in the planned research project. Therefore the reference values have to be determined by empirical studies at intersections with reference character for Swiss conditions. Conditions in towns of different size have to be taken into account. At the coherences between traffic volume and saturation the interactions between vehicles with the right of way and those that have to give way at conflict area are in the foreground. To this corresponding threshold values have to be derived. The reference values of the maximum saturation for pedestrians, bicycles, tramways and busses with the right of way and those that have to give way moreover can be verified due to the results of the ongoing research projects VSS 2007/306 and VSS 2007/305. Due to the new knowledge a new standard concept has to be worked out.2
Publiziert in: Technical report VSS
Band: 2011/308
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Zürich
Publikations-Status: Published
Einordnungen: Ungesteuerte Knoten innerorts, Verkehrsablauf, Verkehrsqualität,, Leistungsfähigkeit, Sättigung, Uncontrolled urban intersections, Traffic flow, Level of service, Capacity, Saturation
Sprache: English
Schlüsselwort: Ungesteuerte Knoten innerorts, Verkehrsablauf, Verkehrsqualität,, Leistungsfähigkeit, Sättigung, Uncontrolled urban intersections, Traffic flow, Level of service, Capacity, Saturation
DBID Quelle: FORM-1422627442
, Menendez, Monica, Guler, S. Ilgin, 2014 >>
Autor(en): Menendez, Monica, Guler, S. Ilgin
Titel: Capacity of multi-modal non-signalized urban intersections
Kurzbeschreibung: 2
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Unpublished
Eventname: VSS quarterly meeting
Eventdatum: February 2014
Ort: Zürich, Switzerland
Sprache: English
DBID Quelle: FORM-1422646369
, Menendez, Monica, Ge, Qiao, Ciuffo, Biagio, 2014 >>
Autor(en): Menendez, Monica, Ge, Qiao, Ciuffo, Biagio
Titel: Sensitivity analysis
Untertitel: A valuable tool in traffic model calibration
Kurzbeschreibung: 2
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Published
Eventname: 20th Conference of the International Federation of Operational Research Societies, IFORS
Eventdatum: July 13-18, 2014
Ort: Barcelona, Spain
Sprache: English
DBID Quelle: FORM-1420730929
, Menendez, Monica, 2014 >>
Autor(en): Menendez, Monica
Titel: The future of mobility
Kurzbeschreibung: 2
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Zürich
Publikations-Status: Unpublished
Eventname: Treffpunkt Science City: TOTAL MOBIL. Ständig unterwegs in Raum, Zeit und Denken
Eventdatum: March 16 - April 13, 2014
Ort: Zurich, Switzerland
Sprache: English
DBID Quelle: FORM-1422646163
, Menendez, Monica, 2014 >>
Autor(en): Menendez, Monica
Titel: Speed and Capacity
Kurzbeschreibung: 2
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Published
Eventname: SVI Serie "Welches Geschwindigkeitsniveau braucht eine Stadt"
Eventdatum: September 16, 2014
Ort: Zürich, Switzerland
Sprache: English
DBID Quelle: FORM-1437807065
, Menendez, Monica, 2014 >>
Autor(en): Menendez, Monica
Titel: Monitoring resources required for traffic perimeter control
Kurzbeschreibung: 2
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Eidhoven, Netherlands
Publikations-Status: Unpublished
Sprache: English
DBID Quelle: FORM-1422646549
, Menendez, Monica, 2014 >>
Autor(en): Menendez, Monica
Titel: Intra- and inter-modal interactions on freeways and urban networks
Kurzbeschreibung: 2
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Zürich
Publikations-Status: Unpublished
Eventname: ASTRA @ HIL
Eventdatum: November 2014
Ort: Zurich, Switzerland
Sprache: English
DBID Quelle: FORM-1422646745
, He, Haitao, Guler, S. Ilgin, Menendez, Monica, 2014 >>
Autor(en): He, Haitao, Guler, S. Ilgin, Menendez, Monica
Titel: Effects of Pre-Signals at an Isolated Intersection: Simulation Results
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Monte Veritá, Ascona, Switzerland
Publikations-Status: Published
Eventname: 14th Swiss Transport Research Conference (STRC 2014)
Eventdatum: May 14-16, 2014
Ort: Monte Verità, Ascona, Switzerland
Sprache: English
DBID Quelle: FORM-1401942331
, He, Haitao, Guler, Ilgin S., Menendez, Monica, 2014 >>
Autor(en): He, Haitao, Guler, Ilgin S., Menendez, Monica
Titel: The effects of pre-signals at an isolated intersection: Simulation results
Kurzbeschreibung: A pre-signal is an additional signal upstream of the main signal which can be used to provide bus priority. Its primary purpose is to allow buses to jump the car queues at the intersection while cars can still use all lanes at the main signal to fully utilize the capacity of the intersection. In this way, bus delay at the intersection is reduced without causing extra stress to the overall traffic. The effects of the pre-signals at an isolated intersection was analytically studied by Guler and Menendez and compared to empirical measurement. However, on the arterial and network level, it is very difficult to study the effects analytically and from our best knowledge there does not exist real work examples. Therefore a simulation model is needed. The goal of this research is to validate the simulation approach by showing that on the isolated intersection level a VISSIM simulation model calibrated with the collected empirical data produces similar results. Therefore, it can be used to understand the mechanism behind the operation of pre-signals and can provide direct visual insights into its effects on traffic flow. With the developed micro-simulation, the effect of the red time duration at the presence of buses could be examined. Recommendation could then be given regarding how long this red signal should be when implementing pre-signals.2
Buchtitel: Proceedings of the 14th Swiss Transport Research Conference (STRC 2014)
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Ascona
Publikations-Status: Published
Einordnungen: Pre-signals, Bus priority, Bus operation
Eventname: 14th Swiss Transport Research Conference (STRC 2014)
Eventdatum: May 14-16, 2014
Ort: Ascona, Switzerland
Sprache: English
Schlüsselwort: Pre-signals, Bus priority, Bus operation
DBID Quelle: FORM-1400079045
, Gómez Jiménez, Penelope, Menendez, Monica, Mérida-Casermeiro, Enrique, Oña López, Juan de, 2014 >>
Autor(en): Gómez Jiménez, Penelope, Menendez, Monica, Mérida-Casermeiro, Enrique, Oña López, Juan de
Titel: Bilevel optimization process to estimate O-D matrices in a small network in Zurich
Kurzbeschreibung: In recent years, traffic studies based on Floating Car Data (FCD) have gained importance due to their manifold advantages compared to classic survey methods, such as paper diaries or telephone interviews. In reality, however, FCD reliability remains an issue due to several error sources. This unreliability limits the use of the FCD to directly solve any transport problem, as some additional information is typically required. In this paper a methodology is introduced to use FCD data in combination with loop detector data for the estimation of origin-destination matrixes. We also determine the expected accuracy of the methodology for different levels of FCD penetration and loop detector coverage; and illustrate the minimum requirements for a given accuracy threshold. The proposed method, a Bilevel Optimization (BO) using fuzzy logic theory, is used with data from a microscopic traffic simulation of the inner city of Zurich, Switzerland. The methodology is illustrated with a simple example of an intersection. Results indicate that the proposed methodology is sound, and can produce highly accurate results given some level of data. Overall, it seems that a 40% FCD penetration rate can ensure errors smaller than 10% independently of any level of loop detector coverage. Evidently, in the presence of high levels of loop detector coverage, the required FCD penetration rate to ensure a 90% accuracy goes down significantly. Similarly, a 75% FCD penetration rate ensures almost 100% accuracy even in the absence of loop detectors.2
Seiten: submission_670
Edition: 11 p.
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Santander
Publikations-Status: Published
Eventname: 18th Pan-American Conference on Traffic and Transportation Engineering (PANAM 2014)
Eventdatum: June 11-13, 2014
Ort: Santander, Spain
Sprache: English
DBID Quelle: FORM-1420719073
, Guler, S. Ilgin, Menendez, Monica, 2014 >>
Autor(en): Guler, S. Ilgin, Menendez, Monica
Titel: Evaluation of pre-signals at oversaturated signalized intersections
Kurzbeschreibung: One of the major causes of bus delays in urban environments are signalized intersections. A commonly used solution to give priority to buses at signalized intersections is to dedicate a lane for bus-use only. This strategy allows the bus to skip the car queues and minimizes the bus delay experienced due to the signal. However, especially for low bus flows, it can also waste valuable green time at signals and impose additional car delays. Overall, even when bus passengers enjoy reduced travel times, the total person hours of delay in the system (i.e., buses and cars) can increase due to excessive delays experienced by car users, particularly when total vehicle demand exceeds the capacity of the signalized intersection. To avoid this, and in order to utilize the full capacity of the main signal while still providing bus priority, the use of a pre-signal (i.e., an additional signal upstream of the main signal) has been proposed. The goal of this research is to quantify the benefits of using pre-signals in terms of system-wide total person hours of delays specifically for over saturated intersections. Theoretical formulae are developed to quantify the effects of a pre-signal on traffic flow, and these formulae are empirically verified. Using the theoretical model, the total delay with a pre-signal strategy is compared to the total delay of implementing a dedicated bus lane, or having fully mixed lanes. Bounds on bus to car occupancy ratios for which pre-signals provide the lowest delay as compared to a dedicated lane or mixed lane strategy are quantified. The end results show that for over saturated intersections, pre-signals are always better for the system than dedicated bus lanes. Moreover, they can decrease the total person hours of delay as compared to mixed lanes for large car demands.2
Publiziert in: Transportation research record
Band: 4
Ausgabe: 2418
ISSN: 0361-1981, 2169-4052
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Washington, D.C.
Publikations-Status: Accepted
Einordnungen: Umwelt, Verkehr, Geographie|Environment, Traffic, Geography
Sprache: English
DBID Quelle: FORM-1392996175
Nebis System Nummer: 000024408
, Guler, S. Ilgin, Menendez, Monica, 2014 >>
Autor(en): Guler, S. Ilgin, Menendez, Monica
Titel: Evaluation of Presignals at Oversaturated Signalized Intersections
Kurzbeschreibung: One of the major causes of bus delays in urban environments is signalized intersections. A commonly used solution to give priority to buses at signalized intersections is to dedicate a lane for bus use only. This strategy allows the bus to skip the car queues and minimizes the bus delay experienced due to the signal. However, especially for low bus flows, it can also waste valuable green time at signals and impose additional car delays. Overall, even when bus passengers enjoy reduced travel times, the total person hours of delay in the system (i.e., buses and cars) can increase due to excessive delays experienced by car users, particularly when total vehicle demand exceeds the capacity of the signalized intersection. To avoid this, and in order to utilize the full capacity of the main signal while still providing bus priority, the use of a pre-signal (i.e., an additional signal upstream of the main signal) has been proposed. The goal of this research is to quantify the benefits of using pre-signals in terms of system-wide total person hours of delays specifically for over saturated intersections. The total delay with this strategy is compared to the total delay of implementing a dedicated bus lane, or having fully mixed lanes. Bounds on bus to car occupancy ratios for which pre-signals provide the lowest delay as compared to a dedicated lane or mixed lane strategy are quantified. The end results show that for over saturated intersections, pre-signals are always better for the system than dedicated bus lanes. Moreover, they can decrease the total person hours of delay as compared to mixed lanes for large car demands.
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Published
Eventname: 93rd Annual Meeting of the Transportation Research Board (TRB 2014)
Eventdatum: January 12-16, 2014
Ort: Washington, DC, USA
Sprache: English
DBID Quelle: FORM-1393333047
, Guler, S. Ilgin, Menendez, Monica, 2014 >>
Autor(en): Guler, S. Ilgin, Menendez, Monica
Titel: Analytical formulation and empirical evaluation of pre-signals for bus priority
Kurzbeschreibung: One of the major causes of bus delays in urban environments are signalized intersections. A commonly used solution to give priority to buses at signalized intersections is to dedicate a lane for bus-use only. However this strategy can waste valuable green time at signals and impose additional delays to cars, especially when bus flows are low. Overall, the total person hours of delays in the system (i.e., buses and cars) can increase due to excessive delays experienced by car users. To this end, an additional signal upstream of the main signal, called a pre-signal, can be used to better utilize the capacity of the main signal while still providing bus priority to reduce the system-wide person hours of delays.
The aim of this research is to analytically quantify and empirically evaluate the delays encountered by cars and buses with the use of pre-signals. The ultimate goal is to provide domains of applications for the proposed strategy. The paper presents analytical formulations to compute bus and car delays using queuing theory. The analytical models show that for a wide range of cases pre-signals can minimize the system-wide person hours of delays, as compared to dedicating a lane for bus-use only or operating buses and cars completely mixed. The analytical model is validated with empirical data collected at an existing pre-signal, which shows that the delay predictions of the model closely follow reality.
Publiziert in: Transportation research Part B, Methodological
Band: 64
Seiten: 41 - 53
ISSN: 0191-2615
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Amsterdam
Publikations-Status: Published
Einordnungen: Verkehr und Transport|Traffic and Transportation, Pre-signals, Bus lanes, Transit priority, Traffic flow
Sprache: English
Schlüsselwort: Pre-signals, Bus lanes, Transit priority, Traffic flow
DBID Quelle: FORM-1383127608, SCOPUS-84898678990, WOS-000336877300003
DOI: 10.1016/j.trb.2014.03.004
Nebis System Nummer: 000006554
, Guler, Ilgin S., Menendez, Monica, Meier, Linus, 2014 >>
Autor(en): Guler, Ilgin S., Menendez, Monica, Meier, Linus
Titel: Using connected vehicle technology to improve the efficiency of intersections
Kurzbeschreibung: Information from connected vehicles, such as the position and speed of individual vehicles, can be used to optimize traffic operations at an intersection. This paper proposes such an algorithm for two one-way-streets assuming that only a certain percentage of cars are equipped with this technology. The algorithm enumerates different sequences of cars discharging from the intersection to minimize the objective function. Benefits of platooning (multiple cars consecutively discharging from a queue) and signal flexibility (adaptability to demand) are also considered. The goal is to gain insights about the value (in terms of delay savings) of using connected vehicle technology for intersection control. Simulations are conducted for different total demand values and demand ratios to understand the effects of changing the minimum green time at the signal and the penetration rate of connected cars. Using autonomous vehicle control systems, the signal could rapidly change the direction of priority without relying on the reaction of drivers. However, without this technology a minimum green time is necessary. The results of the simulations show that a minimum green time increases the delay only for the low and balanced demand scenarios. Therefore, the value of using cars with autonomous vehicle control can only be seen at intersections with this kind of demand patterns, and could result in up to 7% decrease in delay. On the other hand, using information from connected vehicles to better adapt the traffic signal has proven to be indeed very valuable. Increases in the penetration rate from 0% up to 60% can significantly reduce the average delay (in low demand scenarios a decrease in delay of up to 60% can be observed). That being said, after a penetration rate of 60%, while the delays continue to decrease, the rate of reduction decreases and the marginal value of information from communication technologies diminishes. Overall, it is observed that connected vehicle technology could significantly improve the operation of traffic at signalized intersections, at least under the proposed algorithm.2
Publiziert in: Transportation research. Part C, Emerging technologies
Band: 46
Seiten: 121 - 131
ISSN: 0968-090X
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Oxford
Publikations-Status: Published
Einordnungen: Verkehr und Transport|Traffic and Transportation, Connected vehicle, Traffic control, Intersections, Traffic flow
Sprache: English
Schlüsselwort: Connected vehicle, Traffic control, Intersections, Traffic flow
DBID Quelle: FORM-1403175234, WOS-000343387300008
DOI: 10.1016/j.trc.2014.05.008
Nebis System Nummer: 000889058
, Ge, Qiao, Menendez, Monica, 2014 >>
Autor(en): Ge, Qiao, Menendez, Monica
Titel: An efficient sensitivity analysis approach for computationally expensive microscopic traffic simulation models
Kurzbeschreibung: Microscopic traffic simulators are useful tools for designing, evaluating and optimizing transportation systems. In order for a simulator to accurately describe reality, the corresponding traffic model must be properly calibrated. However, the calibration can be rather difficult when the model is computationally expensive and has many parameters. To overcome these difficulties, Sensitivity Analysis (SA) can be applied as an essential instrument for supporting model calibration. Through SA the practitioners can obtain valuable information about the relationship between model inputs and outputs, and hence focus on the proper set of most influential parameters for the calibration. Notice, however, that many quantitative SA techniques may also fail with computationally expensive models.
To address the above issues, in this paper we developed the quasi-OTEE method, an efficient and qualitative SA approach based on the Elementary Effects (EE) method. The quasi-OTEE approach is able to screen the most influential parameters of a complex model through computing and comparing their Sensitivity Indexes. With the improved sampling strategy, this approach is much more efficient than the original EE method. The approach is validated through a numerical analysis, and a case study of a small synthetic network in Aimsun. A more detailed case study of the Zurich network in VISSIM is then provided to illustrate its application. The results demonstrate that the proposed approach is an effective SA tool for the computationally expensive microscopic traffic models, as well as other complex models in the general scientific community.
Publiziert in: International Journal of Transportation
Band: 2
Ausgabe: 2
Seiten: 49 - 64
ISSN: 2287-7940
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Sandy Bay, TAS
Publikations-Status: Published
Einordnungen: Sensitivity analysis, Quasi-OTEE, Microscopic traffic simulation, Computationally expensive model, Calibration
Sprache: English
Schlüsselwort: Sensitivity analysis, Quasi-OTEE, Microscopic traffic simulation, Computationally expensive model, Calibration
DBID Quelle: FORM-1385467335
DOI: 10.14257/ijt.2014.2.2.04
, Ge, Qiao, Ciuffo, Biagio, Menendez, Monica, 2014 >>
Autor(en): Ge, Qiao, Ciuffo, Biagio, Menendez, Monica
Titel: From theory to practice II
Untertitel: a comprehensive approach for the sensitivity analysis of high dimensional and computationally expensive traffic simulation models
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Published
Eventname: 93rd Annual Meeting of the Transportation Research Board (TRB 2014)
Eventdatum: January 12-16, 2014
Ort: Washington, DC, USA
Sprache: English
DBID Quelle: FORM-1385468027
, Ge, Qiao, Ciuffo, Biagio, Menendez, Monica, 2014 >>
Autor(en): Ge, Qiao, Ciuffo, Biagio, Menendez, Monica
Titel: Comprehensive approach for the sensitivity analysis of high-dimensional and computationally expensive traffic simulation models
Kurzbeschreibung: The reliability of traffic model results is strictly connected to the quality of its calibration. A challenge arising in this context concerns the selection of the most influential input parameters. A model Sensitivity Analysis (SA) should be used with this aim. Unfortunately, due to the limitation of time and computational resources, a proper SA is hardly performed in the common practice. A recent study introduced a methodology based on Gaussian process meta-models for the SA of computationally expensive traffic simulation models. Its main limitation was, however, its dependence on the model dimensionality. When the model has more than 15~20 parameters (depending on its regularity), the estimation of a Gaussian process meta-model (also known as Kriging meta-model) may become problematic. In this light, the SA of high-dimensional and computationally expensive models still remains an issue. In the present paper, the Kriging-based approach has been coupled with another recently developed approach (the quasi-OTEE) for the SA of computationally expensive models. The quasi-OTEE SA can be used to identify the whole sub-set of sensitive parameters of a high-dimensional model, and the Kriging-based SA can then be used to refine the analysis and rank the different parameters of the sub-set in a more reliable way. The application of this new SA method is illustrated with the Wiedemann-74 car-following model. Results show that the new method requires 40 times less model evaluations than a standard variance-based SA in identify the influential parameters and their ranks.2
Publiziert in: Transportation research record
Band: 2422
Seiten: 121 - 130
ISSN: 0361-1981
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Washington D.C.
Publikations-Status: Published
Sprache: English
DBID Quelle: FORM-1393331719, WOS-000343640500015
DOI: 10.3141/2422-14
Nebis System Nummer: 000024408
, Ge, Qiao, Ciuffo, Biagio, Menendez, Monica, 2014 >>
Autor(en): Ge, Qiao, Ciuffo, Biagio, Menendez, Monica
Titel: An exploratory study of two efficient approaches for the sensitivity analysis of computationally expensive traffic simulation models
Kurzbeschreibung: One of themain challenges arising when calibrating a complex traffic simulationmodel concerns the selection of the most important input parameters. The quasi-optimized trajectorybased elementary effects (quasi-OTEE) and the Kriging-based sensitivity analysis (SA) are two recently developed efficient approaches for the SA of computationally expensive simulation models. In this paper, two experimental studies using two different traffic simulation models (i.e., Aimsun and VISSIM) are presented to compare these two approaches and to better understand their advantages and disadvantages. Results show that both approaches are able to identify, to a good degree, the important parameters. In particular, the quasi-OTEE is better for screening the parameters, whereas the Kriging-based SA has higher precision in ranking the parameters. These findings suggest the following rule of thumb for the SA of computationally expensive traffic simulation models: the quasi-OTEE SA can be used first to screen the parameters and to decide which parameters to discard. Then, the Kriging-based SA can be used to refine the analysis and calculate first-order indexes to identify the correct rank of the important parameters.2
Publiziert in: IEEE transactions on intelligent transportation systems
Band: 15
Ausgabe: 3
Seiten: 1288 - 1297
ISSN: 1524-9050
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Piscataway, N.J
Publikations-Status: Published
Einordnungen: Verkehr und Transport|Traffic and Transportation, Calibration, Sensitivity analysis (SA), Traffic simulation model, Uncertainty
Sprache: English
Schlüsselwort: Calibration, Sensitivity analysis (SA), Traffic simulation model, Uncertainty
DBID Quelle: FORM-1385402742, WOS-000337130600034
DOI: 10.1109/TITS.2014.2311161
Nebis System Nummer: 004021565
, Cao, Jin, Menendez, Monica, 2014 >>
Autor(en): Cao, Jin, Menendez, Monica
Titel: On-street parking and its effects on nearby intersections
Kurzbeschreibung: 2
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Zürich
Publikations-Status: Unpublished
Eventname: IVT Seminar
Eventdatum: July 2014
Ort: Zürich, Switzerland
Sprache: English
DBID Quelle: FORM-1409234134
, Cao, Jin, Menendez, Monica, 2014 >>
Autor(en): Cao, Jin, Menendez, Monica
Titel: Macroscopic modelling of parking dynamics in urban networks (Part I)
Kurzbeschreibung: Parking can have a significant impact on transportation systems. Besides the effects on travel demand, the regulation and usage of urban parking can also directly influence traffic performance. The availability of parking and the demand to park, at any given time, influence the trip completion rate, and correspondingly the traffic conditions in the area. In our research, we define several vehicle groups, according to their status concerning parking. For example, vehicles in an area can be grouped into "driving", "searching" and "staying (i.e., parking)". To find the quantity of cars in each vehicle group at a future time, we divide the time period into a number of thin time slices, in which the conditions are assumed to be static. Using probability theory, kinematic flow theory and dimensional analysis, a transition matrix can be developed. Based on that, the quantity of cars driving, parking or searching for parking can be updated over time. Therefore, the model enables us to define, simulate, and quantify the dynamics of the parking process. Furthermore, we are able to estimate different traffic parameters / indicators. The ultimate goal is to evaluate the relationship between urban parking and traffic performance in urban networks. The current study (this paper) is a preliminary part of the research, it quantifies the number of cars that access parking in a time slice analytically (i.e, the number of cars that leave the "searching" group, and join the "staying" group). Numerical examples are given, a program is provided to test the results as well.2
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Ascona
Publikations-Status: Published
Einordnungen: Urban Parking, Transition Matrix, Traffic
Eventname: 14th Swiss Transport Research Conference (STRC 2014)
Eventdatum: May 14-16, 2014
Ort: Ascona, Switzerland
Sprache: English
Schlüsselwort: Urban Parking, Transition Matrix, Traffic
DBID Quelle: FORM-1400078366
, Cao, Jin, Menendez, Monica, 2014 >>
Autor(en): Cao, Jin, Menendez, Monica
Titel: Macroscopic modelling of parking dynamics in urban networks
Kurzbeschreibung: 2
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Zürich
Publikations-Status: Published
Eventname: 14th Swiss Transport Research Conference (STRC 2014)
Eventdatum: May 14-16, 2014
Ort: Ascona, Switzerland
Sprache: English
DBID Quelle: FORM-1400667305
, Cao, Jin, Menendez, Monica, 2014 >>
Autor(en): Cao, Jin, Menendez, Monica
Titel: Generalized effects of on-street parking maneuvers on the performance of nearby signalized intersections
Publiziert in: SVT Working Paper
Band: 73
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Zürich
Publikations-Status: Published
Sprache: English
DBID Quelle: FORM-1408888281
, Cao, Jin, Menendez, Monica, 2014 >>
Autor(en): Cao, Jin, Menendez, Monica
Titel: Effect of On-street Parking on Traffic Throughput at Nearby Intersections
Kurzbeschreibung: An on-street parking maneuver can often start a temporary bottleneck, leading to additional delay endured by the following vehicles. In most cases, the number of vehicles delayed due to a parking maneuver is limited. However, if the maneuver occurs close to a signalized intersection, the delay may linger over multiple cycles, resulting in a degraded performance of the traffic and the intersection. In this paper, we try to define a minimum distance from the parking area to the intersection to avoid such delay. As the throughput reduction at the intersection is highly linked to the lingering delay, it is used as a key indicator of the traffic performance. Based on the hydrodynamic theory of traffic flow, the perturbation caused by the parking maneuver is analyzed. Using dimensional analysis, we illustrated the relation between the background conditions (i.e., traffic demand, signal control settings, duration of the parking maneuver), the distance from the parking area to the intersection, and the throughput reduction at the intersection. Based on this relation, one can find a minimum distance to avoid lingering delay (throughput reduction) when designing the parking area, or, to compute the throughput reduction which is caused by existing on-street parking areas. Numerical examples are provided to illustrate the practical applications. We hope the findings can be used as a basis for developing on-street parking design guidelines.
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Published
Eventname: 93rd Annual Meeting of the Transportation Research Board (TRB 2014)
Eventdatum: January 12-16, 2014
Ort: Washington, DC, USA
Sprache: English
DBID Quelle: FORM-1393333448
, Cao, Jin, Menendez, Monica, 2014 >>
Autor(en): Cao, Jin, Menendez, Monica
Titel: A Parking-State-Based Transition Matrix of Traffic on Urban Networks
Kurzbeschreibung: 2
Publiziert in: SVT Working Paper
Band: 77
Publikationsdatum / Empfangsdatum: 2014-01-01
Publikations-Status: Zürich
Publikations-Status: Published
Sprache: English
DBID Quelle: FORM-1410376914
, Ortigosa, Javier, Menendez, Monica, 2013 >>
Autor(en): Ortigosa, Javier, Menendez, Monica
Titel: Traffic performance impacts of link removal on a grid urban pattern
Kurzbeschreibung: In this paper the authors explore how the traffic performance of a grid street network changes when links are removed. The objectives are: to better understand the behavior of grid-like patterns when dealing with traffic; to evaluate the effects of link removal in the overall traffic performance; and, to explore how far from the full grid pattern, an urban structure can be still considered one. The authors create an abstract grid network composed of 100 nodes and bidirectional streets. A simple demand model is applied to load the network effectively. The objective is to emulate a dense urban environment. The authors develop a static traffic assignment model using the Frank-Wolfe algorithm. The accuracy of this model has been increased by a more detailed intersection modeling scheme. The link removal strategies seek representing both: operational eventualities (blockage of streets), and, city planning policies aiming at recovering space for other activities. Links are removed in different ways: in a total random manner, focusing on the center of the grid, and, focusing on the perimeter of the grid. Up to 30 % of the total links are removed. As it will be seen, the authors analyze the critical points of a grid system when accommodating traffic. The authors show that it is possible to remove a certain percentage of links without worsening traffic conditions excessively. This magnitude is very dependent on the link removal strategy. The authors believe that these results can be very useful for city and traffic planners.2
Buchtitel: TRB 92nd Annual Meeting Compendium of Papers
Seiten: 13-3851
Publikationsdatum / Empfangsdatum: 2013-01-01
Publikations-Status: S.l.
Publikations-Status: Published
Eventname: 92nd Annual Meeting of the Transportation Research Board
Eventdatum: January 13-17, 2013
Ort: Washington, DC, USA
Sprache: English
DBID Quelle: FORM-1348672066
, Ortigosa, Javier, Gayah, Vikash, Menendez, Monica, 2013 >>
Autor(en): Ortigosa, Javier, Gayah, Vikash, Menendez, Monica
Titel: Study of urban grid configurations
Kurzbeschreibung: The city structure (i.e. urban pattern) serves as the main traffic infrastructure and has a prime role accommodating vehicular traffic: it influences both travel demand, and traffic operations. These interactions have actually shaped cities as we know them today. In this paper, we study traffic operations on a grid network with three possible street configurations: bidirectional streets, bidirectional streets with prohibited left turns, and unidirectional streets. To do so, we analyze an abstract grid network that emulates a dense city environment, and evaluate different demands and network sizes using a static macroscopic traffic assignment model with special focus on the delay at intersections. Our results show that unidirectional grids provide the lowest total travel time for a given number of trips, but also require vehicles to travel more distance, which results in higher flows on the network. Bidirectional grids with prohibited left turns seem to offer the best compromise between travel time and distance travelled of the three network types. These results, however, as it is detailed in the paper, are dependent on the simulation employed, especially on the delay formulation, and the characteristics of the networks studied.
Publikationsdatum / Empfangsdatum: 2013-01-01
Publikations-Status: Published
Eventname: 13th Swiss Transport Research Conference (STRC 2013)
Eventdatum: April 24-26, 2013
Ort: Ascona, Switzerland
Sprache: English
DBID Quelle: FORM-1367330026
, Ortigosa, Javier, Gayah, Vikash, Menendez, Monica, 2013 >>
Autor(en): Ortigosa, Javier, Gayah, Vikash, Menendez, Monica
Titel: Study of urban grid configurations
Publikationsdatum / Empfangsdatum: 2013-01-01
Publikations-Status: Published
Eventname: 13th Swiss Transport Research Conference (STRC 2013)
Eventdatum: April 24-26, 2013
Ort: Ascona, Switzerland
Sprache: English
DBID Quelle: FORM-1369230482, FORM-1369230375
, Menendez, Monica, Ortigosa, Javier, Tapia, H., 2013 >>
Autor(en): Menendez, Monica, Ortigosa, Javier, Tapia, H.
Titel: Study on the location of measurement points for traffic perimeter control
Publikationsdatum / Empfangsdatum: 2013-01-01
Publikations-Status: Published
Sprache: English
DBID Quelle: FORM-1369127521
, Menendez, Monica, Ge, Qiao, 2013 >>
Autor(en): Menendez, Monica, Ge, Qiao
Titel: Introduction to Traffic Simulation
Publikationsdatum / Empfangsdatum: 2013-01-01
Publikations-Status: Published
Sprache: English
DBID Quelle: FORM-1374486505
, Menendez, Monica, 2013 >>
Autor(en): Menendez, Monica
Titel: Overview of research in transportation
Publikationsdatum / Empfangsdatum: 2013-01-01
Eventname: First Climate
Eventdatum: May 2013
Ort: Zürich
Sprache: English
DBID Quelle: FORM-1369127700
, Heimgartner, Christian, Menendez, Monica, 2013 >>
Autor(en): Heimgartner, Christian, Menendez, Monica
Titel: Challenges for Better Understanding and Simulating Urban Traffic: The Zurich Experience
Kurzbeschreibung: 2
Buchtitel: Proceedings of the 3rd International Conference on Models and Technologies for Intelligent Transportation Systems 2013
Publiziert in: Verkehrstelematik
Band: 3
Seiten: 11 - 22
ISBN: 978-3-944331-34-8, 3-944331-34-6
Publikationsdatum / Empfangsdatum: 2013-01-01
Publikations-Status: Dresden
Publikations-Status: Published
Eventname: 3rd International Conference on Models and Technologies for Intelligent Transportation Systems, MT-ITS 2013
Eventdatum: December 2-4, 2013
Ort: Dresden, Germany
Sprache: English
DBID Quelle: FORM-1445613616
Nebis System Nummer: 010097896
, Guler, Ilgin S., Menendez, Monica, 2013 >>
Autor(en): Guler, Ilgin S., Menendez, Monica
Titel: Empirical Evaluation of Bus and Car Delays at Pre-signals
Kurzbeschreibung: One of the major causes of bus delays in urban environments are signalized intersections. A commonly used solution to give priority to buses at signalized intersections is to dedicate a lane for bus use only. This strategy allows the bus to skip the car queues and minimizes the delay experienced due to the signal. However, especially when bus flows are low, this strategy can waste valuable green time at signals and impose additional delays to cars. Overall, the total person hours of delay in the system (i.e., buses and cars) can increase due to excessive delays experienced by car users even when bus passengers enjoy reduced travel times. To this end, the use of pre-signals, which is an additional signal upstream of the main signal, has been proposed to utilize the full capacity of the main signal while still providing bus priority. When there are multiple lanes (2 or more) approaching the intersection, and one is dedicated for bus-use only, the idea is to discontinue this bus lane some distance upstream of the intersection. A pre-signal is used to stop cars at this location to provide bus priority. The pre-signal allows cars to use all lanes to discharge from the main signal, except when a bus arrives to this location. At that time, the pre-signal turns red for cars. This allows for buses to maneuver into the intersection without encountering conflicts from cars, and provides bus priority by moving them to the front of the intersection. While pre-signals have been proposed, to the authors' knowledge the realized benefits to buses, and dis-benefits to cars that arise from this strategy have not been quantified. Therefore, the goal of this research is to collect data to empirically quantify the delays encountered by cars and buses with the use of pre-signals. By doing so, a better understanding of the changes in car and bus operations due to interactions between these modes, and the effects of strategies to mitigate these effects can be obtained.
Publikationsdatum / Empfangsdatum: 2013-01-01
Publikations-Status: Published
Eventname: 13th Swiss Transport Research Conference (STRC 2013)
Eventdatum: April 24-26, 2013
Ort: Ascona, Switzerland
Sprache: English
DBID Quelle: FORM-1367320433
, Guler, Ilgin S., Menendez, Monica, 2013 >>
Autor(en): Guler, Ilgin S., Menendez, Monica
Titel: Empirical Evaluation of Bus and Car Delays at Pre-signals
Publikationsdatum / Empfangsdatum: 2013-01-01
Publikations-Status: Published
Eventname: 13th Swiss Transport Research Conference (STRC 2013)
Eventdatum: April 24-26, 2013
Ort: Ascona, Switzerland
Sprache: English
DBID Quelle: FORM-1369132184
, Ge, Qiao, Menendez, Monica, 2013 >>
Autor(en): Ge, Qiao, Menendez, Monica
Titel: An improved approach for the sensitivity analysis of computationally expensive microscopic traffic models
Untertitel: A case study of the Zurich network in VISSIM
Kurzbeschreibung: Microscopic traffic simulators are useful tools for designing, evaluating and optimizing transportation systems. In order for a simulator to accurately describe reality, the corresponding traffic model must be properly calibrated. However, the calibration can be rather difficult when the model is computationally expensive and has many parameters. To overcome these difficulties, Sensitivity Analysis (SA) can be applied as an essential instrument for supporting model calibration. Through SA the practitioners can obtain valuable information about the relationship between model inputs and outputs, and hence focus on the proper set of most influential parameters for the calibration. In this paper we developed an SA approach based on the Elementary Effects (EE) method. It screens the most influential parameters in a complex model through computing the corresponding EE and qualitatively comparing the Sensitivity Indexes. With the improved sampling strategy, this approach is much more efficient than the original EE method. A case study of the Zurich network in VISSIM is included here to illustrate the methodology of the proposed approach. The results demonstrate its efficiency and accuracy. In addition, they show that it can be a very useful tool for the SA of computationally expensive microscopic traffic models like VISSIM, as well as other complex models in the general scientific community.
Publiziert in: Conference proceedings
ISSN: 1073-1652
Publikationsdatum / Empfangsdatum: 2013-01-01
Publikations-Status: Washington, D.C.
Publikations-Status: Published
Einordnungen: Verkehrsplanung, Strassen- und Eisenbahnbau|Traffic, Highway and Railroad Engineering, Verkehr und Transport|Traffic and Transportation
Eventname: 92nd Annual Meeting of the Transportation Research Board
Eventdatum: January 13-17, 2013
Ort: Washington, DC, USA
Sprache: English
DBID Quelle: FORM-1348671965
Nebis System Nummer: 000959737
, Ge, Qiao, Menendez, Monica, 2013 >>
Autor(en): Ge, Qiao, Menendez, Monica
Titel: An improved approach for the sensitivity analysis of computationally expensive microscopic traffic models
Untertitel: A case study of the Zurich network in VISSIM
Publikationsdatum / Empfangsdatum: 2013-01-01
Publikations-Status: Published
Eventname: 92nd Annual Meeting of the Transportation Research Board
Eventdatum: January 13-17, 2013
Ort: Washington, DC, USA
Sprache: English
DBID Quelle: FORM-1369233314
, Ge, Qiao, Menendez, Monica, 2013 >>
Autor(en): Ge, Qiao, Menendez, Monica
Titel: A Simulation Study of the Car-to-X Communication Based Freeway Merge Control
Kurzbeschreibung: The merge control has been proposed as a way to maximize the utilization of road capacity at the work zone area. Two of the most widely used merge control schemes are the static Early Merge (EM) control and the static Late Merge (LM) control. Although many papers adopted field measurements and/or microscopic traffic simulations to explore the performance of these two control schemes, they seldom cross compared them under the same work zone settings, and some of them even derived conflicting results. To extensively investigate and cross compare the traffic performance of the EM and LM controls, we conducted a simulation study using the microscopic traffic simulator VISSIM for a 2-to-1 lane closure work zone. In addition, the sensitivity analysis was adopted to determine the influential VISSIM parameters with respect to the work zone throughput. It is found that the parameters CC1 (i.e., headway time) and CC2 (i.e., longitudinal following threshold in the car-following process) have significant impacts on the simulated work zone throughput. In addition, adjusting CC1 can make the throughput drop faster in the EM scenarios than in the LM scenarios. The simulations also show that when CC1 is low, the work zone capacity under the EM control is higher and the queue is shorter. On the contrary, when CC1 is high, the work zone with LM control has a higher capacity and shorter queue. As the parameter CC1 is critical to the simulation results, it should be carefully calibrated and validated in the VISSIM-based merge control simulations. Based on the simulation results, we recommended that it is more appropriate to implement the EM control when the drivers are aggressive and the safety distance is relatively short (i.e., CC1 is low); when the drivers are cautious and the safety distance is long (i.e., CC1 is high), it is better to adopt the LM control in the work zone area.
Publikationsdatum / Empfangsdatum: 2013-01-01
Publikations-Status: Published
Eventname: 13th Swiss Transport Research Conference (STRC 2013)
Eventdatum: April 24-26, 2013
Ort: Ascona, Switzerland
Sprache: English
DBID Quelle: FORM-1367319939
, Ge, Qiao, Menendez, Monica, 2013 >>
Autor(en): Ge, Qiao, Menendez, Monica
Titel: A Simulation Study for the Static Early Merge and Late Merge Controls at Freeway Work Zones
Kurzbeschreibung: The merge control has been proposed as a way to maximize the utilization of road capacity at the work zone area. Two of the most widely used merge control schemes are the static Early Merge (EM) control and the static Late Merge (LM) control. Although many papers adopted field measurements and/or microscopic traffic simulations to explore the performance of these two control schemes, they seldom cross compared them under the same work zone settings, and some of them even derived conflicting results. To extensively investigate and cross compare the traffic performance of the EM and LM controls, we conducted a simulation study using the microscopic traffic simulator VISSIM for a 2-to-1 lane closure work zone. In addition, the sensitivity analysis was adopted to determine the influential VISSIM parameters with respect to the work zone throughput. It is found that the parameters CC1 (i.e., headway time) and CC2 (i.e., longitudinal following threshold in the car-following process) have significant impacts on the simulated work zone throughput. In addition, adjusting CC1 can make the throughput drop faster in the EM scenarios than in the LM scenarios. The simulations also show that when CC1 is low, the work zone capacity under the EM control is higher and the queue is shorter. On the contrary, when CC1 is high, the work zone with LM control has a higher capacity and shorter queue. As the parameter CC1 is critical to the simulation results, it should be carefully calibrated and validated in the VISSIM-based merge control simulations. Based on the simulation results, we recommended that it is more appropriate to implement the EM control when the drivers are aggressive and the safety distance is relatively short (i.e., CC1 is low); when the drivers are cautious and the safety distance is long (i.e., CC1 is high), it is better to adopt the LM control in the work zone area.
Publikationsdatum / Empfangsdatum: 2013-01-01
Publikations-Status: Published
Einordnungen: Work Zone, Static Merge Control, Microscopic Traffic Simulation, Capacity, Sensitivity Analysis
Eventname: 13th Swiss Transport Research Conference (STRC 2013)
Eventdatum: April 24-26, 2013
Ort: Ascona, Switzerland
Sprache: English
Schlüsselwort: Work Zone, Static Merge Control, Microscopic Traffic Simulation, Capacity, Sensitivity Analysis
DBID Quelle: FORM-1369233437
, Ge, Qiao, Ciuffo, Biagio, Menendez, Monica, 2013 >>
Autor(en): Ge, Qiao, Ciuffo, Biagio, Menendez, Monica
Titel: Quasi-OTEE versus Kriging-based approach for the sensitivity analysis of computationally expensive traffic simulation models
Untertitel: An exploratory study
Kurzbeschreibung: Sensitivity Analysis (SA) is widely used in the calibration of traffic simulation models: it provides the modeler better knowledge about the relationship between model inputs and outputs, so the calibration can focus on the most important parameters. However, when the model is computationally expensive and has many parameters, many SA techniques (e.g., Monte Carlo approaches) are unfeasible due to the high computational cost.
Publikationsdatum / Empfangsdatum: 2013-01-01
Publikations-Status: Published
Eventname: 7th International Conference on Sensitivity Analysis of Model Output (SAMO)
Eventdatum: July 1-4, 2013
Ort: Nice, France
Sprache: English
DBID Quelle: FORM-1374757620
, Cao, Jin, Vasileios, Nikias, Menendez, Monica, 2013 >>
Autor(en): Cao, Jin, Vasileios, Nikias, Menendez, Monica
Titel: On-street parking near intersections
Untertitel: Effects on traffic
Kurzbeschreibung: An on-street parking maneuver can often start a temporary bottleneck, leading to additional delay endured by following vehicles. In most cases, the number of vehicles delayed due to a parking maneuver is limited. However, if the maneuver occurs close to a signalized intersection, it may result in a capacity loss at the intersection and the delay could linger over multiple cycles. In this paper, we try to define a minimum distance from the parking area to the intersection to avoid loss of capacity and enhance traffic performance. Using dimensional analysis, the effect of duration of parking maneuver, traffic flow condition, and the distance from parking area to intersection on the capacity loss at intersections is illustrated. The final results will hold for a broad range of cases, and can be used as a basis for developing on-street parking area design guidelines.
Publikationsdatum / Empfangsdatum: 2013-01-01
Publikations-Status: Published
Eventname: 13th Swiss Transport Research Conference (STRC 2013)
Eventdatum: April 24-26, 2013
Ort: Ascona, Switzerland
Sprache: English
DBID Quelle: FORM-1367318124
, Cao, Jin, Nikias, Vasileios, Menendez, Monica, 2013 >>
Autor(en): Cao, Jin, Nikias, Vasileios, Menendez, Monica
Titel: On-street parking near the intersections
Untertitel: Effects on traffic
Kurzbeschreibung: 2
Publikationsdatum / Empfangsdatum: 2013-01-01
Publikations-Status: Published
Eventname: 2nd Symposium of the European Association for Research in Transportation (hEART 2013)
Eventdatum: September 4-6, 2013
Ort: Stockholm, Sweden
Sprache: English
DBID Quelle: FORM-1380126068
, Cao, Jin, Nikias, Vasileios, Menendez, Monica, 2013 >>
Autor(en): Cao, Jin, Nikias, Vasileios, Menendez, Monica
Titel: On-street parking near intersections
Untertitel: Effects on traffic
Kurzbeschreibung: 2
Publikationsdatum / Empfangsdatum: 2013-01-01
Publikations-Status: Published
Eventname: 13th Swiss Transport Research Conference (STRC 2013)
Eventdatum: April 24-26, 2013
Ort: Ascona, Switzerland
Sprache: English
DBID Quelle: FORM-1367918323
, Cao, Jin, Menendez, Monica, 2013 >>
Autor(en): Cao, Jin, Menendez, Monica
Titel: Methodology to evaluate cost and accuracy of parking patrol surveys
Kurzbeschreibung: Patrol surveys are frequently used to estimate average parking duration. However, error in estimating is unavoidable and yet unpredictable. It is, therefore, hard for surveyors to decide on survey budgets; lower ones may generate unusable results and higher ones are costly. Therefore, a method to evaluate and improve survey accuracy without increasing (and possibly even lowering) cost could be highly beneficial. In this paper, an analytical model is built to determine the effects of survey budget on survey accuracy in a systematic and generalized way. The relationship between the survey budget, the estimated average parking duration (i.e., the survey result), and the survey error is illustrated through dimensional analysis. On the basis of this analysis, objective criteria are found to evaluate patrol surveys, a budget test is provided to find the optimal survey budget, and a correction method is proposed to improve survey accuracy. Moreover, simulations are run on the basis of more realistic assumptions, so that the conclusions from the analytical model can be extended to real life situations. The model is well validated with real parking data. An example application is also provided that illustrates how to use the proposed approaches to choose a survey budget and to improve survey accuracy. It is hoped that this study will help surveyors to better understand patrol surveys and obtain high-quality results, while keeping costs to a minimum.2
Publiziert in: Transportation research record : journal of the Transportation Research Board
Band: 2359
Seiten: 1 - 9
ISSN: 0361-1981
Publikationsdatum / Empfangsdatum: 2013-01-01
Publikations-Status: Washington, DC
Publikations-Status: Published
Einordnungen: Umweltproblematik allgemein|Environmental Problems, General
Eventname: 92nd Annual Meeting of the Transportation Research Board
Eventdatum: January 13-17, 2013
Ort: Washington, DC, USA
Sprache: English
DBID Quelle: FORM-1348672172, SCOPUS-84886621102
DOI: 10.3141/2359-01
Nebis System Nummer: 000024408
, Cao, Jin, Menendez, Monica, 2013 >>
Autor(en): Cao, Jin, Menendez, Monica
Titel: Methodology for evaluating cost and accuracy of parking patrol surveys
Publikationsdatum / Empfangsdatum: 2013-01-01
Publikations-Status: Published
Eventname: 92nd Annual Meeting of the Transportation Research Board
Eventdatum: January 13-17, 2013
Ort: Washington, DC, USA
Sprache: English
DBID Quelle: FORM-1369312694
, Arnet, Kathrin, Ortigosa, Javier, Menendez, Monica, 2012 >>
Autor(en): Arnet, Kathrin, Ortigosa, Javier, Menendez, Monica
Titel: Traffic Management in the Inner City of Zurich
Kurzbeschreibung: 2
Publiziert in: NSL-Newsletter
Band: 14
Publikationsdatum / Empfangsdatum: 2012-06-01
Publikations-Status: Zürich
Publikations-Status: Published
Sprache: English
DBID Quelle: FORM-1345672439
, Ortigosa, Javier, Menendez, Monica, Tapia, H., 2012 >>
Autor(en): Ortigosa, Javier, Menendez, Monica, Tapia, H.
Titel: Study on the location of measurement points for an MFD perimeter control scheme in Zurich
Publiziert in: EURO Journal on Transportation and Logistics
ISSN: 2192-4384, 2192-4376
Publikationsdatum / Empfangsdatum: 2012-01-01
Publikations-Status: Berlin
Publikations-Status: Accepted
Sprache: English
DBID Quelle: FORM-1354367191
, Ortigosa, Javier, Menendez, Monica, Bodenbender, Anne-Kathrin, 2012 >>
Autor(en): Ortigosa, Javier, Menendez, Monica, Bodenbender, Anne-Kathrin
Titel: Link removal on a grid street network
Kurzbeschreibung: This paper explores some properties of a grid street network when accommodating traffic flows under different demand scenarios. The abstract street network considered is a graph defined by nodes and links. The shape of the region is square, therefore the grid is composed of regular squares. Demand is concentrated on the nodes. However, in order to compare different topologies, the total number of trips generated and attracted will be the same independently of the number of nodes (i.e. a model with lesser nodes will concentrate more demand on them). A triangular model, where the trips increase with distance, is proposed. A static macroscopic traffic assignment model has been developed and applied using the Frank-Wolfe algorithm. The travel time is modeled according to the Bureau of Public Roads travel time function, adapted to urban areas. The grid pattern is initially complete (i.e. all the nodes connected according to the grid model). Links are subtracted gradually from the grid in a random manner. For every subtraction, network descriptors are re-calculated. These descriptors are basically related to the density and connectivity of the network (e.g. gamma index). At the same time, for every network configuration, the demand is allocated using the traffic assignment algorithm mentioned above. The traffic performance is then measured using as main inputs the speed and the flows on links, the distance travelled, and the travel time. This iterative process allows us to plot some relationships between the physical characteristics of the network and the traffic performance.
Publikationsdatum / Empfangsdatum: 2012-01-01
Publikations-Status: Ascona
Publikations-Status: Published
Einordnungen: Grid, Traffic performance, Connectivity, Static traffic assignment
Eventname: 12th Swiss Transport Research Conference (STRC 2012)
Eventdatum: May 2-4, 2012
Ort: Ascona, Switzerland
Sprache: English
Review-Status: Peer reviewed
Schlüsselwort: Grid, Traffic performance, Connectivity, Static traffic assignment
DBID Quelle: FORM-1338380962, FORM-1348671109
, Ortigosa, Javier, Menendez, Monica, Bodenbender, Anne-Kathrin, 2012 >>
Autor(en): Ortigosa, Javier, Menendez, Monica, Bodenbender, Anne-Kathrin
Titel: Link removal on a grid street network
Publikationsdatum / Empfangsdatum: 2012-01-01
Publikations-Status: Published
Eventname: 12th Swiss Transport Research Conference (STRC 2012)
Eventdatum: May 2-4, 2012
Ort: Ascona, Switzerland
Sprache: English
DBID Quelle: FORM-1352443333
, Ortigosa, Javier, Arnet, Kathrin, Menendez, Monica, 2012 >>
Autor(en): Ortigosa, Javier, Arnet, Kathrin, Menendez, Monica
Titel: Studying the feasibility of a MFD control in Zürich
Publikationsdatum / Empfangsdatum: 2012-01-01
Publikations-Status: Published
Eventname: 1st European Symposium on Quantitative Methods in Transportation Systems
Eventdatum: September 4-7, 2012
Ort: Lausanne, Switzerland
Sprache: English
DBID Quelle: FORM-1348670284
, Menendez, Monica, Tapia, H., Ortigosa, Javier, 2012 >>
Autor(en): Menendez, Monica, Tapia, H., Ortigosa, Javier
Titel: Macroscopic traffic controls in the city of Zürich
Publikationsdatum / Empfangsdatum: 2012-01-01
Eventname: Vereinigung der Kader des Bundes (VKB) Meeting
Eventdatum: September 2012
Sprache: English
DBID Quelle: FORM-1347888712
, Menendez, Monica, Ortigosa, Javier, 2012 >>
Autor(en): Menendez, Monica, Ortigosa, Javier
Titel: Traffic performance and networks
Publikationsdatum / Empfangsdatum: 2012-01-01
Publikations-Status: Published
Sprache: English
Review-Status: Unknown
DBID Quelle: FORM-1339150526
, Menendez, Monica, 2012 >>
Autor(en): Menendez, Monica
Titel: ZurichLAB
Publikationsdatum / Empfangsdatum: 2012-01-01
Publikations-Status: Published
Eventname: Modelling and Simulation group meeting within the Division of Transport for the City of Zurich
Eventdatum: November, 2012
Ort: Zürich, Switzerland
Sprache: English
DBID Quelle: FORM-1354289115
, Menendez, Monica, 2012 >>
Autor(en): Menendez, Monica
Titel: Visionary Mobility
Publikationsdatum / Empfangsdatum: 2012-01-01
Publikations-Status: Published
Eventname: 6th HSG Alumni Zürich Flagship Event
Eventdatum: November 19, 2012
Ort: Zürich, Switzerland
Sprache: English
DBID Quelle: FORM-1354288762
, Menendez, Monica, 2012 >>
Autor(en): Menendez, Monica
Titel: Urban Structure and Traffic Performance
Publikationsdatum / Empfangsdatum: 2012-01-01
Publikations-Status: Published
Eventname: Netzwerk Stadt und Landschaft: Werkdiskussion 2012
Eventdatum: November 12, 2012
Ort: Zürich, Switzerland
Sprache: English
DBID Quelle: FORM-1354288545
, Menendez, Monica, 2012 >>
Autor(en): Menendez, Monica
Titel: SVT: INTERACTION and other ASTRA projects
Publikationsdatum / Empfangsdatum: 2012-01-01
Publikations-Status: Published
Sprache: English
DBID Quelle: FORM-1354289260
, Menendez, Monica, 2012 >>
Autor(en): Menendez, Monica
Titel: I Can Start a Research Group, Now What?
Publikationsdatum / Empfangsdatum: 2012-01-01
Publikations-Status: Published
Eventname: COTA Professional Development Forum for Young Scholars and Students: Innovations and Best Practices in Transportation Education
Eventdatum: August 3-6, 2012
Ort: Beijing, China
Sprache: English
Review-Status: Unknown
DBID Quelle: FORM-1345618377
, Menendez, Monica, 2012 >>
Autor(en): Menendez, Monica
Titel: Controlling Traffic in Zurich
Untertitel: A Macroscopic Approach
Publikationsdatum / Empfangsdatum: 2012-01-01
Publikations-Status: Published
Eventname: 12th COTA International Conference of Transportation Professionals (CICTP 2012)
Eventdatum: August 3-6, 2012
Ort: Beijing, China
Sprache: English
Review-Status: Unknown
DBID Quelle: FORM-1345618483
, Ge, Qiao, Menendez, Monica, 2012 >>
Autor(en): Ge, Qiao, Menendez, Monica
Titel: Using VISSIM to model traffic in the city of Zürich
Publikationsdatum / Empfangsdatum: 2012-01-01
Publikations-Status: Published
Eventname: IVT-Alumni-Seminar : Verkehrsingenieurtag 2012
Eventdatum: March 8, 2012
Ort: Zürich, Switzerland
Sprache: English
Review-Status: Unknown
DBID Quelle: FORM-1339150930
, Ge, Qiao, Menendez, Monica, 2012 >>
Autor(en): Ge, Qiao, Menendez, Monica
Titel: Sensitivity analysis for calibrating VISSIM in Modeling the Zurich Network
Publikationsdatum / Empfangsdatum: 2012-01-01
Publikations-Status: Published
Eventname: 12th Swiss Transport Research Conference (STRC 2012)
Eventdatum: May 2-4, 2012
Ort: Ascona, Switzerland
Sprache: English
DBID Quelle: FORM-1352443750
, Ge, Qiao, Menendez, Monica, 2012 >>
Autor(en): Ge, Qiao, Menendez, Monica
Titel: Sensitivity Analysis of a Microscopic Traffic Model
Publikationsdatum / Empfangsdatum: 2012-01-01
Publikations-Status: Zürich
Publikations-Status: Published
Eventname: IVT-Alumni-Seminar : Verkehrsingenieurtag 2012
Eventdatum: March 8, 2012
Ort: Zürich, Switzerland
Sprache: English
DBID Quelle: FORM-1345623236
, Ge, Qiao, Menendez, Monica, 2012 >>
Autor(en): Ge, Qiao, Menendez, Monica
Titel: Sensitivity Analysis for Calibrating VISSIM in Modeling the Zurich Network
Kurzbeschreibung: In the last few decades microscopic traffic simulation has grown into a major resource for the researchers and practitioners in the field of traffic engineering. The use of commercial traffic simulators (i.e., software) has become widespread, and these programs have indeed become necessary tools for planning and designing transportation networks. In order for a traffic simulator to accurately describe reality, it must be supported by a valid traffic model, and it must be properly calibrated.VISSIM is one of the most widely used microscopic traffic simulators with many applications and high potential. However, like other commercial microscopic traffic simulators, VISSIM has a very large number of input parameters which makes the model calibration rather difficult. In addition, if the spatial scope of the modeled network is quite large, the calibration will usually be very time consuming. In order to overcome these difficulties, a Sensitivity Analysis (SA) is essentially required as a preliminary step for the model calibration. Through SA the modeler can obtain a better knowledge about the relationship between the model inputs and outputs, and hence focus on the most important parameters for further calibration. This paper is based on a research project to calibrate the VISSIM network model for the inner city of Zurich. The complex network of the inner city makes the computational cost of running the simulation very expensive. Therefore it does not allow using a brute force approach to do the SA. An improved SA method, which is based on the Elementary Effects method, was proposed and applied in this project. This method reduced the computation time required for the SA from 77 days to 2 days for this specific case. The results are presented in this paper. They show that the proposed method is accurate and efficient, especially for dealing with the SA of complex VISSIM networks.
Publikationsdatum / Empfangsdatum: 2012-01-01
Publikations-Status: Published
Einordnungen: Sensitivity Analysis, Elementary Effects Method, Microscopic Traffic Simulation, Network Model Calibration
Eventname: 12th Swiss Transport Research Conference (STRC 2012)
Eventdatum: May 2-4, 2012
Ort: Monte Verità, Ascona
Sprache: English
Schlüsselwort: Sensitivity Analysis, Elementary Effects Method, Microscopic Traffic Simulation, Network Model Calibration
DBID Quelle: FORM-1338376462, FORM-1348671365
, Ge, Qiao, Menendez, Monica, 2012 >>
Autor(en): Ge, Qiao, Menendez, Monica
Titel: A Simulation Study of the Car-to-X Communication Based Merge Traffic Control in Freeway Work Zone
Publikationsdatum / Empfangsdatum: 2012-01-01
Publikations-Status: Published
Eventname: 1st European Symposium on Quantitative Methods in Transportation Systems
Eventdatum: September 4-7, 2012
Ort: Lausanne, Switzerland
Sprache: English
DBID Quelle: FORM-1348670168
, Cao, Jin, Menendez, Monica, 2012 >>
Autor(en): Cao, Jin, Menendez, Monica
Titel: Methodology for evaluating cost and accuracy of parking patrol surveys
Publiziert in: Schriftenreihe
Publikationsdatum / Empfangsdatum: 2012-01-01
Publikations-Status: Published
Eventdatum: December, 2012
Ort: Zürich, Switzerland
DBID Quelle: FORM-1354289935
Nebis System Nummer: 005022139
, Cao, Jin, Menendez, Monica, 2012 >>
Autor(en): Cao, Jin, Menendez, Monica
Titel: Accuracy study of parking duration data from patrol survey
Kurzbeschreibung: Patrol survey is a widely used method for data collection in parking studies, and one of its goals is to obtain the average parking duration for a parking area. However, the inaccuracy is unavoidable; one main reason is that short stay vehicles are often not observed. To reduce the error from the survey, short observation intervals can be chosen, but that can be very expensive. In this article, a generalized analytical model is built to analyse this error, several suggestions are made to guarantee the accuracy, and to coordinate it with the survey costs. Through dimensional analysis, the relation between time length of observation interval, estimated parking duration, and survey accuracy is illustrated. In the numerical example, a correction for the value of average duration is introduced to increase the accuracy. We further used simulation-based examples to extend the model and the conclusions to more generalized situations. The final result shows that with this approach, the accuracy of the survey could be estimated and enhanced. It helps the surveyors in choosing a proper length for the survey interval, so one could obtain high quality results from the patrol survey while keeping costs to a minimum.2
Publikationsdatum / Empfangsdatum: 2012-01-01
Publikations-Status: Published
Einordnungen: Average parking duration, Parking behavior, Patrol survey, Data collection–, Parking duration accuracy
Eventname: 12th Swiss Transport Research Conference (STRC 2012)
Eventdatum: May 2-4, 2012
Ort: Monte Verità, Ascona
Sprache: English
Schlüsselwort: Average parking duration, Parking behavior, Patrol survey, Data collection–, Parking duration accuracy
DBID Quelle: FORM-1338373510, FORM-1348670775, FORM-1348670775
, Cao, Jin, Menendez, Monica, 2012 >>
Autor(en): Cao, Jin, Menendez, Monica
Titel: Accuracy Study of Parking Duration Data from Patrol Survey
Publikationsdatum / Empfangsdatum: 2012-01-01
Publikations-Status: Published
Eventname: 12th Swiss Transport Research Conference (STRC 2012)
Eventdatum: May 2-4, 2012
Ort: Ascona, Switzerland
Sprache: English
DBID Quelle: FORM-1352443527
, Arnet, Kathrin, Ortigosa, Javier, Ge, Qiao, Menendez, Monica, 2012 >>
Autor(en): Arnet, Kathrin, Ortigosa, Javier, Ge, Qiao, Menendez, Monica
Titel: Study of traffic management strategies in the Zürich area
Publikationsdatum / Empfangsdatum: 2012-01-01
Publikations-Status: Published
Eventname: IVT-Alumni-Seminar : Verkehrsingenieurtag 2012
Eventdatum: March 8, 2012
Ort: Zürich, Switzerland
Sprache: English
Review-Status: Unknown
DBID Quelle: FORM-1339151071
, Menendez, Monica, Ge, Qiao, 2011 >>
Autor(en): Menendez, Monica, Ge, Qiao
Titel: Sensitivity analysis in calibration of traffic microscopic models
Publikationsdatum / Empfangsdatum: 2011-01-01
Publikations-Status: Published
Eventname: COST workshop for MULTITUDE project
Eventdatum: November 24-25, 2011
Ort: Ispra, Italy
Sprache: English
Review-Status: Unknown
DBID Quelle: FORM-1339150688
, Menendez, Monica, Ge, Qiao, 2011 >>
Autor(en): Menendez, Monica, Ge, Qiao
Titel: Analysis and calibration of VISSIM
Publikationsdatum / Empfangsdatum: 2011-01-01
Publikations-Status: Published
Eventname: COST workshop for MULTITUDE project
Eventdatum: June 27-28, 2011
Ort: Stockholm, Sweden
Sprache: English
Review-Status: Unknown
DBID Quelle: FORM-1339150617
, Lee, Joon H., Menendez, Monica, Cassidy, Michael, 2011 >>
Autor(en): Lee, Joon H., Menendez, Monica, Cassidy, Michael
Titel: Lane-changes and their effects on freeway weaving bottlenecks
Publikationsdatum / Empfangsdatum: 2011-01-01
Publikations-Status: Published
Eventname: 11th Swiss Transport Research Conference (STRC 2011)
Eventdatum: May 11-14, 2011
Ort: Ascona, Switzerland
Sprache: English
Review-Status: Unknown
DBID Quelle: FORM-1339150828
, Menendez, Monica, 2010 >>
Autor(en): Menendez, Monica
Titel: Traffic operations with special lanes
Publikationsdatum / Empfangsdatum: 2010-01-01
Publikations-Status: Published
Sprache: English
Review-Status: Unknown
DBID Quelle: FORM-1339150415
, Menendez, Monica, 2010 >>
Autor(en): Menendez, Monica
Titel: Analysis of HOV lanes
Untertitel: Their impact on traffic
Publikationsdatum / Empfangsdatum: 2010-01-01
Publikations-Status: Lausanne
Publikations-Status: Published
Sprache: English
DBID Quelle: FORM-1339150303

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