A Study on Setting Program for Intermittent Bus Lanes at Urban Road Intersections

The bus priority policy would cause the delay of social vehicles. In order to improve the travel efficiency of social vehicles at urban signalized intersections and maximize the lane capacity on the premise of ensuring bus priority. A type of intermittent bus lane (IBL) operation mode at urban road intersections is proposed, allowing social vehicles to enter the bus lane when bus traffic is not disturbed. The type of vehicle at the entrance of intersections is control by setting pre-signals to achieving time-sharing of the bus exclusive lanes. A model of cellular automaton with three-lane is established considering signal coordination and lane-changing rules. A modified speed benefit model is used to simulate the operation status of bus lanes. A lane-changing pressure model is used to simulate the mandatory lane-changing rules in the clearing area. The effectiveness of IBL at intersections is measured using the evaluation indicators including speed, queuing, and delay time of vehicles. The results indicate that: ① When the traffic volume is less than 50% of the lane capacity, the average delay and queueing time of social vehicles under the IBL mode decrease by 6.9% and 4.9% respectively, the average speed of buses increases by 3% and the average delay of buses decreases by 5% comparing to those under the mode of traditional bus exclusive lanes. ② When the traffic volume reaches 50% to 80% of the lane capacity, the average speed of social vehicles increases by 15% to 37% and the average delay decreases by 8% to 20%. However, the average speed of buses decreases by 3.4% and the average delay increases by 5.7%. ③ When the traffic volume exceeds 80% of the lane capacity, the average speed of social vehicles increases by 6.7% and the average delay time decreases by 5.8%. However, and the average delay time of buses increases by 28.2%. Anactual unban intersection is selected as an empirical case study to verify the feasibility of IBL, which shows that the use of IBL can significantly reduce queuing time during off-peak hours and under the moderate traffic volume context.