Abstract: When the driver of a small vehicle on the inner lane of the expressway discovered and read the roadside traffic sign information, due to the reasons such as the parallel of multiple vehicles, the drivers sight may be blocked by the large vehicle on the outer lane, which caused the driver to miss important traffic information. Therefore, the probability of the small vehicle drivers sight on the inner lane blocked by the large vehicle on the outer lane within the scope of traffic sign recognition was studied and the probability calculation model for the driver missing the roadside traffic sign information was established, which was based on the shortest time required for the driver to read traffic signs, the distribution of vehicle headway, the geometric relationship between the drivers sight and vehicles and lanes, and the principle of calculus. The proposed model was tested by VISSIM traffic simulation software. The results show that the change of the traffic volume of the small vehicles on the inner lane has less influence on the probability of the small vehicle driver missing the traffic sign information. The increase of the total number of large vehicles on the outer lane will increase the probability of the small vehicle driver on the inner lane missing the traffic sign information. When the speed of small vehicles on the inner lane is constant, the increase of the speed of large vehicles on the outer lane will reduce the probability of the small vehicle driver on the inner lane missing traffic signs. When the speed of large vehicles on the outer lane is constant, the probability of the driver of the small vehicle missing the traffic sign information increases as the speed of the small vehicle on the inner lane increases. In the case of the equal speed difference between the inner and outer lanes, the probability of small vehicle drivers missing traffic signs decreases with the increase of vehicle speed.

Key words: traffic engineering, roadside traffic sign, occlusion, missing traffic sign information, VISSIM traffic simulation

摘要： 高速公路上内侧车道小型车辆驾驶员在发现和阅读路侧交通标志信息时，因多车并行等原因，会出现驾驶员视线被外侧车道上大型车辆所遮挡情况，导致驾驶员错过重要的交通信息。为此，基于驾驶员认读交通标志所需的最短时间、车辆车头时距分布、驾驶员视线与车辆、车道形成的几何关系及微积分原理，对交通标志视认范围内内侧车道小型车辆驾驶员视线被外侧车道大型车辆遮挡概率进行研究，建立驾驶员错过路侧交通标志信息的概率计算模型，并通过VISSIM交通仿真软件对该模型进行检验。结果表明：内侧车道上小型车辆交通量的变化对小型车辆驾驶员错过交通标志信息的概率的影响较小；外侧车道大型车辆总量的增加会使内侧车道小型车辆驾驶员错过交通标志信息的概率增大；内侧车道小型车辆在速度一定的情况下，外侧车道大型车辆速度的提高会降低内侧车道小型车辆驾驶员错过交通标志信息的概率；外侧车道大型车辆在速度一定的情况下，小型车辆驾驶员错过交通标志信息的概率随着内侧车道上小型车辆速度的提高而增大；内外侧车道上车辆在等速差的情况下，小型车辆驾驶员错过交通标志信息的概率随着车速的增加而降低。

关键词: 交通工程, 路侧交通标志, 遮挡, 错过交通标志信息, VISSIM交通仿真