Abstract:In order to eliminate the bottleneck effect of left-turn traffic on at-grade intersection, the traffic organization mode of bow-tie-shaped intersection is used to prohibit the vehicles turning left at intersection. The left-turn vehicles are led to turn round at the ring island of secondary road. The left-turn traffic is changed into straight traffic. According to the vehicle speed, road and traffic conditions, the calculation models of distance, radius and lane width between the ring island and the intersection are deduced. The traffic organization of the bow-tie-shaped intersection prohibits the vehicles at intersection to turn left. The conflict point is reduced and the signal control is only two phases. The utilization rate of signal lamp can be improved at intersection, and the operation efficiency of intersection has the remarkable improvement effect.