Co-ordinated Operation of Queues at Congested Arterial Signalised Intersections

Abstract

Urban traffic congestion is a pressing issues in terms of transportation in cities. Traffic control is essential to tackle this problem and an optimised traffic signal timing strategy is one of the most cost-effective ways to achieve improvements. The importance of queue management strategies at signalised road intersections is well-known in this context and modern traffic control strategies are capable of handling queueing vehicles efficiently during light traffic conditions. The most common approach to intersection management is to minimise the overall delays, primarily considering the aggregated delay of vehicles waiting during the red phase for each approach. These strategies are usually limited to isolated intersections, but attention to network-wide solution has steadily increased. In particular, arterial road management is challenging due to the number of movements (lane groups) to co-ordinate at each junction and the inherent variations in arrival rates and trajectories (e.g. straight on, right turners, etc.). To overcome the limitations of other queueing models at arterial roads, it is necessary to devise control strategies which account for prevailing intersections conditions and moving queues (platoons) of vehicles approaching from upstream. Furthermore, adaptive management uses multiple queue control objectives, the most commonly used being to minimise delay, maximise capacity or synchronise queue clearance.