NTC@Maryland Sponsored Seminar Series “Effectiveness of Variable Speed Limits”

On May 8th, 12:00 to 1:30 PM, Prof. Yafeng Yin from University of Florida visited the National Transportation Center @ Maryland and gave a research presentation in the DeWalt Conference Suite, 2164 Glenn Martin Hall, University of Maryland, College Park.

The talk examines the effectiveness of variable speed limits (VSLs) on improving traffic flow efficiency and reducing vehicular emissions in a stylized setting of morning commute where a fixed number of individuals commute from home to workplace through a single bottleneck. They consider a VSL system installed along the freeway toward the bottleneck, which adjusts commuters' cruising speeds in a discrete fashion and essentially regulates the upstream flow into the bottleneck. By investigating the departure-time equilibrium under the proposed VSL system, we establish conditions for the system to improve various performance measures and then bound its efficiency. Based on empirical data, they conclude that the proposed VSL system can avoid or postpone the capacity drop associated with an active bottleneck and thus reduce queuing delay. It also helps reduce the schedule delay cost and total emissions cost. However, it is unlikely for the system to reduce total travel time, individual travel cost and social cost. Their results shed light on the effectiveness of VSL systems on realistic freeway networks.

Dr. Yafeng Yin is an Associate Professor at Department of Civil and Coastal Engineering and the Director of Transportation Research Center, University of Florida. He works in the areas of transportation systems analysis and modeling, and has published over 70 refereed papers in leading academic journals. He is an Associate Editor for Transportation Research Part C, and Journal of Advanced Transportation, an Area Editor for Journal of Transportation Safety and Security, and serves on the editorial boards of Transportation Research Part B, ASCE Journal of Infrastructure Systems, International Journal of Sustainable Transportation, and Journal of Intelligent Transportation Systems. He is also a member of Transportation Network Modeling Committee of Transportation Research Board. Dr. Yin received his Ph.D. from the University of Tokyo in 2002, his master's and bachelor's degrees from Tsinghua University in 1996 and 1994 respectively. Prior to his current appointment at the University of Florida, he worked as a postdoctoral researcher at University of California at Berkeley between 2002 and 2005. Between 1996 and 1999, he was a lecturer at Tsinghua University, Beijing.

Published May 12, 2014