Coordination of agent-based control in a freeway network

The steadily increasing numbers and lengths of traffic jams on freeways have led to the use of dynamic traffic management (DTM) measures all over the world. Ramp metering control has proven to be one of the most efficient means to reduce freeway congestion. It is expected that integrated and coordinated application of DTM measures will further improve its impact. This paper studies a new coordinated ramp metering control algorithm called HERO/RWS. This algorithm has been developed for the current Dutch ramp metering systems and it will be applied on the Amsterdam A10 freeway network in the near future. The aim of this algorithm is to postpone congestion on freeways by effectively using ramp storage space from upstream on-ramps. The control scheme is simple and real-time operable. VISSIM-based microscopic simulation results show that the HERO/RWS coordinated control outperforms non-coordinated control. This control algorithm turns out to provide less congestion, higher mean speeds and lower travel time spent on the freeway.