A Modified Coordinated Ramp Metering Strategy

With the goal of resolving the problem of traffic congestion in urban traffic system and freeway networks, after a overview of proposed and implemented intersection control strategy and ramp-metering strategy, there is a modified ramp-metering strategy provided in this paper. The new approach is based on the ALINEA with a quene balance phase is added, to get rid of the unfairness of ALINEA. The main idea is to calculate online the unfairness of two adjacent on-ramp applied ALINEA, when the unfairness exceeds a pre-defined threshold a quene balance phase then initiated, which let upstream ramps reduce their outflow and downstream ramps increase their outflow, to reduce the unfairness. Nu-merical examples are presented showing the new strategy can significantly increase the fairness within ramps without losing the efficience and simpleness of ALINEA.