Optimal traffic lights control using meta heuristic algorithms in high priority congested networks.

There is a need for gating in some parts of an urban network that have higher priority especially during peak hours. This article presents a developed model, which we named internal-external traffic metering strategy (IETMS), begins with maximizing the offset in entering arterials of protected sub-network. The first step requires an accurate evaluation of optimal queue length in upstream arterials. In the second step, traffic light schedules are optimized in entering arteries. This optimization is done based on maximizing the traffic entry flow of arterials to the sub-network, keeping queue length close to its optimal amount and preventing extreme oscillations in green time through cycles. The congestion rate inside the protected area will remain below its critical value in this condition. Results show that using the novel IETMS model not only causes gating in the subnetwork but also improves total throughput of the network in such a way that the average speed and delay have had 14 and 19% improvement, respectively. [ABSTRACT FROM AUTHOR]