研究城市立交匝道连接点临界间隙,建立了右转机动车穿越直行自行车的临界间隙模型.在分析驾驶员对直行自行车反应的基础上,以匝道连接点的几何特性和右转机动车的运行为研究内容,利用机动车穿越时间法,得到临界间隙的估算模型.通过北京市西直门和蓟门桥的模型计算值与实测估计值比较,相对误差分别为5.1%和9.6%,说明本模型具有很好的准确性和实用性. The critical clearance between right-turn vehicles and straight-ahead bicycles is established based on the study of the critical clearances of the junctions of urban interchanges.After analyzing the reaction of drivers to straight-ahead bicycles, taking the geometrical characteristics of the ramp connecting points and the right-turning vehicles as Research content and vehicle crossing time method to obtain the critical clearance estimation model.Compared with the measured and estimated values ​​of Xizhimen and Jimen Bridge in Beijing, the relative errors are 5.1% and 9.6%, respectively, indicating that this model has very good Good accuracy and practicality.