车速对交通事件影响区安全与通行效率的影响

The Influence of Speed on Traffic Safety and Efficiency Within Impact Zone of Traffic Incident

选取高速公路交通事件下交通冲突率和车速标准差作为安全表征指标,车辆排队长度为效率表征指标,通过对交通事件下车辆跟驰、换道安全间隙和车速标准差与事故率关系的分析,建立VISSIM仿真模型,分析车速对事件上游影响区运行安全的影响,并根据交通流理论分析车速对通行效率的影响。研究结果表明:事件影响区冲突率和警告区冲突率随车速增加而增加;上游过渡区冲突率在交通量较小时(1 800 pcu/h≤Q≤2 100 pcu/h)随车速的增加而增加,在交通量较大时(2 100 pcu/h≤Q≤2 400 pcu/h)受车速影响较小;车速标准差和事故率随车速和交通量的增加而增加;事件上游影响区内运行效率随车速的增加先增大后减小。

Conflict frequency and speed standard deviation is selected as safety indicators for highway and line length is selected as the efficiency indicator. VISSIM simulation model is established to analyze the safety spaces for lane changing and the relationship between velocity standard deviation and accident frequency in case of traffic incident. In addition,the influence of speed on traffic safety in the upstream impact zone of traffic incident is investigated. Based on the traffic flow theory,the influence of speed on traffic flow efficiency is analyzed. The results show that the conflicts in influence region and warning area increase with speed. In the upstream influence region,the conflicts increase with speed if traffic volume is from 1 800 pcu / h to 2 100 pcu /h. However,the conflicts due to speed are comparatively limited if traffic volume is from 2 100 pcu / h to 2 400 pcu / h. Speed standard deviation and accident frequency increases with speed and traffic volume. The operation efficiency in the upstream influence zone of traffic incident increases first and then decreases with speed.