基于事故特征耦合影响的城市道路交通事故影响分析

A Traffic Impact Analysis of Urban-road Traffic Accidents Based on Coupling Influences of Accident Characteristics

城市道路交通事故发生后,由于事故车辆占用车道,使得车辆通行的车道数目减少,道路的通行能力降低,造成排队和交通拥堵,对交通运行产生一定的影响。以双向6车道的城市道路为例,运用Vissim仿真软件模拟交通事故下的交通运行,分析车流量、占道类型、事故持续时间以及借道超车4种因素下的交通影响。结果表明,流量越大、事故持续时间越长、占道数目越多,事故对交通的影响越大。当流量达到3400 veh/h(D级服务水平),占1个车道的车辆延误显著增加,直至流量达到4000 veh/h时才逐渐趋于平稳,且占据车道2比占据车道1和占据车道3的延误要大;当流量达到1900 veh/h(B级服务水平),占2条车道的车辆延误显著增加直至流量达到2700 veh/h时才逐渐趋于平稳,占据车道1和3的车辆延误要小于占据车道1和2以及占据车道2和3的延误;在相同占道情况下,不同事故持续时间下的车辆延误随流量变化的趋势大体是一致的;当事故道路服务水平为D/E/F级,对向道路服务水平在A/B/C/D级时(事故占用内侧1个车道),以及当对向道路服务水平在A/B/C级时(事故占据内侧2个车道),进行借道超车均能有效减少事故路段车辆延误。

After an urban road traffic accident,the number of lanes for the vehicle to pass and the capacity of urban roads are reduced due to lane occupation by accident vehicles.It causes queuing and traffic congestion,which affects traffic operations.A two-way six-lane urban road is taken as a case study.The traffic operation under traffic accidents is simulated by Vissim simulation software,with the traffic impact under four factors analyzed:traffic flow,occupation type,incident duration,and overtaking on the lane.The results show that greater traffic flow means longer incident du⁃ration,more occupied roads,and greater traffic accidents.When the traffic volume reaches 3400 veh/h(level-D ser⁃vice),the delay of vehicles occupying one lane increases significantly until the traffic volume reaches 4000 veh/h;the delay of occupying lane 2 is greater than that of occupying lanes 1 and 3.When the traffic volume reaches 1900 veh/h(level-B service),the delay of vehicles occupying two lanes increases significantly until the traffic volume reaches 2700 veh/h,which gradually stabilizes.Under the same occupation situation,vehicle delays with the traffic flow under different incident durations are generally the same.When the service levels of the accident road are D,E,and F,with the service levels A,B,C,and D of the opposite road(the accident occupies one lane inside)and the ser⁃vice levels A,B,and C of the opposite road(the accident occupies two lanes inside),tailgating and overtaking can reduce the vehicle delay on the accident road section.