异常事件下高速道路交通状态的分析与仿真

为了考察异常事件对高速道路交通运行的影响,对事发后高速道路局部交通状态的演变过程进行了分解,分析了各阶段的事发点通行能力,并将事发点通行能力的影响因素归纳为事件性质、阻塞行车道宽度、事件发生位置、现场行车秩序与上游交通量等五类,针对交通事故引起局部车道临时关闭这一典型的异常事件,进行微观交通仿真。仿真结果表明:行车延误随着车道关闭开始大幅度增长,直至车道开放,之后开始降低,整个演变过程伴随着波动;当交通量接近于道路通行能力时,交通流系统处于脆弱的平衡状态,异常事件极易引起大范围、长时间的交通拥堵,此时,应采取交通诱导和匝道控制等必要的措施来转移部分交通量,减小异常事件的影响。

Analysis and simulation of traffic state on expressway during incident

In order to research the influence of incident on the traffic operation of expressway,the process of local traffic state during incident was disassembled,the capacity in each phase was analyzed,the affecting factors of the capacity were induced to incident feature,blocked width,incident position,travelling order and upstream traffic volume,and traffic microsimulation was carried out when accident results to the closure of some lanes.Simulation result shows that traffic delay increases quickly during the closure till the lanes are opened,then starts to decrease,there are some fluctuations in the whole process;when traffic volume approaches capacity,the balance of traffic system is weak,incident will arouse traffic congestion in large area and long time,some necessary measures,such as traffic routing and ramp control,should be adopted to divert traffic volume partially and reduce incident influence.1 tab,10 figs,11 refs.