基于网络变结构优化的大型活动交通拥堵预防方法

Traffic congestion prevention method during large-scale special events based on variable network topology optimization

为了降低道路交通拥堵发生的风险和应对成本,基于网络变结构基础模型,提出适应大型活动拥堵预防的中微观层面的网络变结构优化方法和流程.分别建立路段和交叉口变结构模型,以复合饱和度最小为路段变结构的优化目标,以进口各相位流量比之和最小为交叉口变结构的优化目标.结合大型活动交通运行和拥堵演化特征,提出网络变结构关键路段的概念及识别原则,设定受影响路段双向交通重要度权重,将交叉口变结构作为路段变结构的连带、辅助策略,研究优化模型的解法,并以北京首都体育馆一次大型活动散场交通为案例,对提出方法进行实证研究.结果表明,在研究范围内实施变结构优化可以预防活动诱增交通引发的拥堵,有利于解决严重的交通方向不均衡问题,各相关路段复合饱和度改善比例均超过10%,表明所提方法能有效调节网络交通供需的短时结构性不匹配,在现有条件下优化交通基础设施存量而避免增量造成的资源浪费,是以精细化管控为导向的方法.

A set of methodology and process of variable network topology optimization at the middle and micro view level for large-scale special events congestion prevention was proposed based on the basic model,in order to reduce the risk and the combating costs of road traffic congestion.The variable topology models of roadway sections and intersections were established respectively,with the minimum composite saturation degree as the optimization objective of the roadway section variable topology,and the minimum sum of volume ratios of various phases on the approach as the optimization objective of the intersection variable topology.The concept and the identification principles of the key roadway sections of the variable network topology were proposed,the two-way traffic importance weights of the affected roadway sections were set,and the intersection variable topology was used as the joint and auxiliary strategy for roadway section variable topology combined with the traffic operation and congestion evolution characteristics of the large-scale special events.The optimization model solution methods were also studied.The empirical study of the proposed method was based on the leaving traffic of a large-scale special event held in Capital Indoor Stadium in Beijing.Results show that the implementation of variable topology optimization in the study area can prevent congestion caused by special event attracted traffic,which is conducive to solving the problem of serious imbalances of two-way traffic directions.The improvement percentage of composite saturation degree on all relevant roadway sections was more than 10%,indicating that the proposed method can effectively adjust the short-term structural mismatch of network traffic supply and demand,and optimize the transportation infrastructure stock under existing conditions to avoid the waste of resources caused by infrastructure increases,and it is a fine management oriented method.