Variable Speed Limit: An Overview and Case Study of Sayad Shirazi Highway

A part of the existing congestion in highways is built by drivers’ spontaneous behavior when using transportation infrastructures. If such behaviors are replaced by controlled behaviors using dynamic traffic management measures, there will be a significant improvement in highways traffic condition. One of the most recent and efficient techniques of traffic management for controlling traffic flow in highways is known as variable speed limits. This article aims to discuss how variable speed limits are used to improve the traffic condition and presents how this recently introduced technique works. Sayad Shirazi Highway has been selected as the case study. An algorithm has been suggested and the evaluated using AIMSUN simulator. The most important results of the simulation are a noticeable 10.96 percent reduction in delay and 9.06 percent shorter total travel time.