Bus Priority Signal Control Strategy for Intersections without Bus Lanes

Giving priority to buses at intersections can increase the attraction of buses. A typical bus priority control strategy consists of two parts: identifying the bus priority request and estimating the time needed to reach the stop line; and adjusting the signal timing accordingly. One major challenge is that buses may queue up when approaching the intersection, which makes the time estimation difficulty. This happens frequently when exclusive bus lanes are not available. Therefore, a bus priority signal control strategy is developed. The time needed for a bus to reach the stop line is estimated once the bus is detected, and updated if the bus joins a queue. Green extension and phase switch rules are determined by bus priority requests in the current and conflicting phases. Simulation tests show that the proposed strategy can greatly reduce the average bus delay on the cost of slightly increasing average delay of private vehicles.