Network impacts of a road capacity reduction: Empirical analysis and model predictions
In spite of their widespread use in policy design and evaluation, relatively little evidence has been reported on how well traffic equilibrium models predict real network impacts. Here we present what we believe to be the first paper that together analyses the explicit impacts on observed route choice of an actual network intervention and compares this with the before-and-after predictions of a network equilibrium model. The analysis is based on the findings of an empirical study of the travel time and route choice impacts of a road capacity reduction. Time-stamped, partial licence plates were recorded across a series of locations, over a period of days both with and without the capacity reduction, and the data were 'matched' between locations using special-purpose statistical methods. Hypothesis tests were used to identify statistically significant changes in travel times and route choice, between the periods of days with and without the capacity reduction. A traffic network equilibrium model was then independently applied to the same scenarios, and its predictions compared with the empirical findings. From a comparison of route choice patterns, a particularly influential spatial effect was revealed of the parameter specifying the relative values of distance and travel time assumed in the generalised cost equations. When this parameter was 'fitted' to the data without the capacity reduction, the network model broadly predicted the route choice impacts of the capacity reduction, but with other values it was seen to perform poorly. The paper concludes by discussing the wider practical and research implications of the study's findings.
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Availability:
- Find a library where document is available. Order URL: http://worldcat.org/issn/09658564
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Supplemental Notes:
- Abstract reprinted with permission from Elsevier.
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Authors:
- Watling, David
- Milne, David
- Clark, Stephen
- Publication Date: 2012-1
Language
- English
Media Info
- Media Type: Print
- Features: Figures; References; Tables;
- Pagination: pp 167-189
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Serial:
- Transportation Research Part A: Policy and Practice
- Volume: 46
- Issue Number: 1
- Publisher: Elsevier
- ISSN: 0965-8564
- Serial URL: http://www.sciencedirect.com/science/journal/09658564
Subject/Index Terms
- TRT Terms: Alternatives analysis; Empirical methods; Highway capacity; Mathematical prediction; Route choice; Traffic assignment; Traffic equilibrium; Traffic models
- Uncontrolled Terms: Day-to-day variability; Network models; Reduction (Decrease)
- Subject Areas: Highways; Planning and Forecasting; I72: Traffic and Transport Planning;
Filing Info
- Accession Number: 01359063
- Record Type: Publication
- Files: TRIS
- Created Date: Dec 16 2011 2:48PM