Effects of Variable Speed Limit on Energy Consumption with Autonomous Vehicles on Urban Roads Using Modified Cell-Transmission Model

Autonomous vehicles create new opportunities for innovative intelligent traffic systems. Variable speed limit (VSL), which is a speed management system that can adjust the speed limit according to traffic conditions or a predefined speed control algorithm on different road segments, can be better implemented with the cooperation of autonomous vehicles. These compliant vehicles can automatically follow speed limits. However, noncompliant vehicles will attempt to pass the moving bottleneck created by compliant vehicles. This study builds a multiclass cell-transmission model (CTM) to represent the relation among traffic flow parameters. This model calculates flows of both compliant and noncompliant vehicles between road segments. An VSL algorithm is proposed to reduce the stop-and-go behavior of vehicles at traffic signals and to save energy consumption. Simulation is used to test the effects of VSLs on an example network. The result shows that VSLs are effective at reducing the energy consumption of the whole system.