基于拥堵概率的城市快速路入口匝道控制策略

Ramp Metering Strategy for Urban Expressway Based on Breakdown Probability

为解决城市快速路交通拥挤问题,开展快速路入口匝道控制策略研究.采用现行规范与现场数据建立VISSIM微观仿真模型,基于交通仿真分析,建立快速路入口合流区的拥堵概率模型,提出基于拥堵概率的入口匝道控制策略.通过收集主线上游流量以及入口匝道流量,预测拥堵概率;若拥堵概率超过其临界值,则启用入口匝道控制系统,确定匝道入口调节率和信号周期.研究表明,相比无信号控制,基于拥堵概率的快速路入口匝道控制策略能够使拥堵概率降至0.1左右,主线车速提高约20%.

To release and solve traffic jam on expressway, it is necessary to investigate the ramp metering strategy of expressway. Current specification and field data were used to build the VISSIM simulation model. The breakdown probability models of expressway ramp were established by microscopic traffic simulation, and a ramp metering strategy based on breakdown probability model was put forward. According to the mainstream and ramp volume, the breakdown probability was predicted. If the probability is higher than the threshold, the metering system turns on, and the on-ramp metering rate and cycle time are calculated. Compared with a ramp without metering strategy, the breakdown probability reduced to about 0.1, while the speed of mainstream increased by about 20 %.