基于最大熵的城郊公路接入口安全间距研究

Study on access safety spacing of suburban highways using maximum entropy principle

为研究接入口间距对城郊公路的道路通行能力和交通安全状况的影响,通过实地调研,大量采集城郊公路的车辆运行速度、交通量等数据,据此提出接入口间距的定义,并依据最大熵原理构建模型。运用Matlab软件计算出模型最优解,进而确定城郊公路接入口安全间距为120-140 m。然后用仿真软件Synchro,对不同接入口间距进行仿真。结果表明,随着接入口间距增大,车均延误、停车次数不断减小,平均车速不断增大;当接入口间距大于120 m时,3个指标趋于稳定。最后,以太原城郊公路小牛线为例,验证该接入口安全间距值能满足通行能力和安全视距的要求。

For the sake of studying effects of access spacing on the road capacity and traffic safety situation of the suburban highway,extensive data on speed and traffic volume of suburban highways were collected through field investigation. Firstly,a definition was put forward for the access spacing. On the basis of the maximum entropy principle a model was built for the spacing by using the collected data. Matlab software was used for calculating the optimal solution of the model. The conclusion is that 120-140 m can be considered as the safety access spacing. Simulation software Synchro was used for simulating different access spacing arrangement scenarios. Simulation results show that increasing the access spacing,means reducing average vehicle delay and the number of stops,and increasing the average speed of the vehicle,and the 3 indexes are stable when the access spacing was more than 120 m. Finally,the safety access spacing was verified by the example of Xiaoniu line.