基于交通冲突技术的交织区交通安全评价

为了分析城市快速路多个交织区之间的相对交通安全状况,及比选同一个交织区的多个设计方案,建立基于交通冲突技术的交织区交通安全评价方法。首先,使用微观交通仿真软件模拟一定道路交通条件下车流运行状态及其随时空变化的过程,并生成车辆轨迹文件;然后,运用交通安全替代评价模型(SSAM)分析车辆轨迹文件,识别和统计交通仿真过程中"发生"的交通冲突;最后,以交织区交通冲突数与交织区交通量、交织区长度的比值作为评价指标,评价交织区的交通安全状况。案例分析表明,交织区交通冲突率越高,其服务水平往往越低;交织区的交通冲突率有随交织区交通量增加而增加,随交织区长度、交织区车道数的增加而降低的趋势。

Evaluation of Weaving Sections with Respect to Traffic Safety Based on Traffic Conflict Technique

To compare weaving segments and their alternative project designs on the basis of traffic safety,a method to evaluate weaving segments with respect to traffic safety was presented based on the traffic conflict technique.First,VISSIM was used to predict the performance of new weaving segments and export vehicle trajectory data.Then SSAM was employed to implement conflict analysis of vehicle trajectory data.Finally,the ratios of the number of traffic conflicts to total traffic volume and the length of the weaving segments were adopted as the evaluation index of traffic safety.The application shows that ratio of traffic conflict increases as level of service decays,and that ratio of traffic conflict increases with an increase in traffic volume and decreases with an increase in weaving length and number of lanes.