Abstract
An automatic traffic congestion system implemented on the Tomei Expressway is described. The system provides vehicles in congested queue with real time information on head of queue to stimulate drivers to accelerate from the queue and to increase queue discharge flow. It uses various data collected to automatically select the appropriate messages for each VMS for display. The queue discharge flow was increased by 1.6-7.0% depending upon each bottleneck with an average of 3.2% for eastbound section and 3.8% for westbound section. Assuming a 3% increase in the queue discharge flow, traffic congestion was reduced by nearly 40%.