Conditional Bus Signal Priority Strategies Considering Saturation Degree Restriction at Isolated Junction

To reduce the negative effect on general traffic caused by bus signal priority (BSP), a conditional priority methodology that considers the saturation degree restriction in the premise that no traffic congestion occurs at the intersection was brought forward, and two bus signal priority strategies, with or without green time compensation to non-priority phase, were established. The two strategies were tested in the VISSIM environment and compared with non-priority strategy and unconditional BSP strategy. The results show that the two strategies proposed outperform the non-priority strategy by 22.9% and 15.1%, respectively, in reducing the average bus delay in all scenarios, and outperform the unconditional BSP strategy by 10.7% and 16.5%, respectively, in reducing the increase of average vehicle delay in the scenarios with high bus frequency or high saturation degree