弯道下坡路段单点超速抓拍设置位置模型

Setting Location Model for Single Point Overspeed Snapping System in Bend Downhill

为解决单点超速抓拍(以下简称超速抓拍)设置位置按经验法确定主观性强、效果弱问题,基于汽车动力学和能量守恒原理,综合考虑驾驶员视认特性,分析了在超速抓拍路段上,超速抓拍-车辆-弯道下坡三者的协调关系,建立了超速抓拍设置位置模型.采用最不利于安全的汽车行驶特性和驾驶员特性参数计算得出不同初速度、目标速度和减速度下的设置位置.以云梧高速公路八个安设超速抓拍路段为例,对比实际位置与模型计算位置的差异,分析超速抓拍安装前后追尾事故的绝对事故率和事故强度变化规律.结果表明,七个路段超速抓拍的实际位置同模型计算位置的差异与追尾事故变化是一致的.

In order to solve the problems of strong subjectivity and weak effect in determining the setting position of single-point overspeed snapshot by empirical method, based on the principles of vehicle dynamics and energy conservation, and considering the visual recognition characteristics of drivers, the coordination relationship between overspeed snapshot, vehicle and downhill curve on the overspeed snapshot section was analyzed, and the setting position model of overspeed snapshot was established. The setting positions under different initial speeds, target speeds and deceleration were calculated by using the vehicle driving characteristics and driver characteristics parameters which are most unfavorable to safety. Taking 8 sections of Yunwu Expressway installed with overspeed snapshot as an example, the absolute accident rate and the change rule of accident intensity before and after the installation of overspeed snapshot were analyzed by comparing the difference between the actual position and the calculated position of the model. The results show that the difference between the actual position of speeding snapshot and the calculated position of the model is consistent with the change of rear-end collision.