Freeway Traffic Control in the Presence of Capacity Drop

摘要

Capacity drop at congested freeway bottlenecks is well known with a lot of field observations. This paper addresses coordinated ramp metering and mainstream traffic flow control (MTFC) on freeways with capacity drop. The two control measures were first checked with respect to active bottlenecks with capacity drop. It was illustrated that the significance and usefulness of the control measures are very much justified by the presence of capacity drop in field. Coordinated ramp metering, MTFC, and their integration were formulated in an optimal control framework. It was demonstrated via macroscopic simulation studies that an appropriate usage of the control measures can effectively prevent the activation of potential bottlenecks on freeways and hence avoid capacity drop there.