Optimal Cycle Model Based on Active Transit Signal Priority Strategies with Artery Coordination

Studies about Active Transit Signal Priority(Active TSP) mainly focus on benefits and parameters of priority strategies under given cycle time,which is not necessarily the optimal cycle.Considered the restriction brought by arterial coordination,the quantified impact of 3 typical Active TSP strategies on vehicle delay in key intersection on arterial road was discussed.Optimal cycle model based on maximum possible benefits of priority strategies was formed.With a real case,the effect of possible real volume variation on optimal cycle under Active TSP strategies was analysed.The results show that(1) under special traffic volume combination,increasing cycle time generated by TRRL approach can achieve extra benefit;(2) the increasing degree can rise with the increase of the ratio of priority phase's volume to non-priority phase's volume,and the cycle time can be set dynamically according to volume condition in real operation;(3) the efficacy of red truncation is better than that of green extension.