Optimizing the Use of Partial Information in Urban and Regional Systems - OPUS

IVT Partners

Imperial College London (CTS)
Transport for London
Katalysis Consulting Limited
Facultés Universitaires Notre Dame de la Paix (FUNDP)
Systematica s.r.l.
PTV Planung Transport Verkehr AG
World Health Organization (WHO)

Project Researchers

K.W. Axhausen
J. Hackney
S. Chalasani

Sponsors

European Union 5th RTD Framework Programme

Period of Research

05.2003 - 05.2006

Summary

The OPUS project will contribute to improved decision making in the public and private sector within Europe by developing innovative statistical and database systems to enable the combination of data from disparate cross-sectoral sources. The key scientific objective of the project is to develop a generic statistical framework for the optimal combination of complex spatial and temporal data from survey and non-survey sources. The framework will be sufficiently abstract to be applicable in a potentially wide range of socio-economic domains. It will be demonstrated in transport pilot applications in London and Zurich and in smaller-scale feasibility studies in a number of other cities and regions, and in a feasibility study in the health sector.

The transport pilot applications will involve the definition of specific structural relationships between measured quantities and the characterization of sampling/non-sampling errors, based on domain knowledge from the field of transport planning. The necessary database and estimation software to enable the application of the statistical framework to mobility will be developed.

There is currently no statistically coherent methodology to address general problems of data combination in the transport, health and environment sectors. The success of the work will be measured by the extent to which the models and methods developed can be demonstrated to lead to improved estimates of key policy relevant parameters. Two factors will constitute the relevant "efficiency indicators" for the project and will enable the benchmark comparison of results across space and time. The first is a measure of the improvement in the combination and use of data sources that were hitherto incommensurate. The second is a demonstrable improvement in the accuracy and/or precision of estimated parameters.

IVT is active in WP5 (Consistency Testing), WP9 (Zurich Case Study), and WP12 (Assessment and Evaluation)

WP5 Consistency Testing

The principal objective of this work package is to test the overall consistency and feasibility of the approach before the software development takes place.

There will be a number of elements to this work:

• Review of definitions and data flow to check the consistency of the items and their interfaces
• Cross check of model assumptions and data situation, using the later case study cities as standards of reference
• Review of model assumptions with regards to realism and acceptability for the case study cities

The work will involve a series of workshops between the model developers and the partners involved in this work package to allow for an on-going programme of revisions and improvements to the modelling approach.

WP9 Zurich Case Study

The aims of this work package are to:

• Prove the methodology in a practical context with real data
• Capture benefits for the OPUS project objectives, from the information and modelling infrastructure being developed in London (Transport for London).
• Provide concrete improvements to the policy monitoring and modelling methodology available in Zurich
• To demonstrate, conjointly with the pilot application in London, the transferability of the OPUS methodology across different national and application contexts

The case study will use three types of data from regular on-going surveys to update travel patterns in Zurich.

1. Travel data from a single member of sample households
2. On-board sample bus surveys
3. Automatically collected traffic flow data

It is anticipated that the facilities of the LATS study database system and those developed in WP6 (Database Systems) will be valuable to reduce the effort otherwise required by this work package on data conversion and processing issues.

Once the data has been prepared and fed into the data estimation process, the results will be analysed to determine the effects of different data types on the estimation. It may be anticipated that various data issues and optimisation details will be observed at this stage; these will be resolved as far as resources permit, but the main aim will be to gain understanding of the process rather than conduct a formal updating process.

WP12 Assessment and Evaluation

The aims of this work package are to:

• Design a means of evaluating the performance of the statistical methods and software developed in the project, in the case study application in London and Zurich
• To undertake an evaluation of the pilot applications, using this methodology.

This work package will provide an independent evaluation of the effectiveness of the methods in a practical application. It will concentrate on validation of results and examine the extent to which the results represent an improvement on previous methods.
In particular, validation will concentrate on:

• The extent to which component sub-models have been fitted by the methods employed
• The errors inherent in the combination of data from different sources
• Examination of global indicators, such as journey length distributions
• Observable validation results with respect to the data to be fitted (traffic flows and passenger movements), including data used in the process and independent data
• The separability of the validation and whether sampling from the results proves the stability of the approach.

Although the main part of the evaluation work will be concentrated in the final year (reflecting the timing of the case studies), evaluation will be an ongoing activity throughout the project.

Further information

Research Database Project 13342