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Research Projects

STATUS: Complete YEAR: 2018 TOPIC AREA: Integrating freight and passenger systems Vehicles and infrastructure CENTER: PSR

Get More Out of Variable Speed Limit Control: An Integrated Approach to Manage Traffic Corridors with Multiple Bottlenecks

Project Summary

Project number: PSR-18-21

Funding source: US DOT

Funding amount: $116,813

Contract number: 69A3551747109

Start and end dates: October 1, 2018 to December 31, 2019


Project description

The model based variable speed limit (VSL) control has been proven effective to resolve capacity-drop and time delay at a single recurrent bottleneck in previous studies. This project applies VSL controls to the traffic corridors with multi-segment and multi-bottleneck with the objective of reducing fuel consumption and greenhouse gas emissions. Based on a comprehensive review of existing methods, we develop and compare two fuel consumption centered VSL control (FC-VSL) strategies: flow-based control versus density-based control. These control strategies are implemented in SUMO, a microscopic traffic simulation package, on a 10-mile long freeway section. Results show that the density-based control reduces fuel consumption and gas emissions significantly at the cost of slight increase of travel time. The flow-based control, in contrast, reduces congestion and emissions in the downstream segments but transfers the congestion to the segments upstream of the controlled segments, resulting in an overall performance that is worse than the density-based FC-VSL, and no better than imposing static speed limits.


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Michael Zhang
Professor, Department of Civil and Environmental Engineering
3145 Ghausi Hall
Davis, CA 95616
United States
[email protected]