基于速度变化的偶发性交通拥堵时空分布特性研究

交通事故的发生会引起其上游路段通行速度的下降和交通流量的堆积，从而引发交通拥堵.本文主要研究了城市道路中交通事故引起的交通拥堵的时空分布特征.首先，基于北京市事故数据和路段速度数据分析交通事故影响下的车辆速度变化特性；接着，根据交通事故信息和事故路段流量与速度数据，建立了一种基于速度差异的拥堵判定模型，并对其时空维度的约束条件加以限定.在此基础上对事故引发的拥堵时空范围进行量化描述；最后，依托仿真数据与北京市真实事故数据进行效果验证.结果表明，该方法可以有效地描述交通事故引起的拥堵时空分布特性.

Spatial and Temporal Distribution of Occasional Congestion Based on Speed Variation

The occurrence of traffic accidents will lead to the decrease of traffic speed and the accumulation of traffic flow in the upstream section, thus causing traffic congestion. This paper studies the spatial and temporal distribution characteristics of traffic congestion caused by traffic accidents on urban roads. Firstly, the vehicle speed variation characteristics under the impact of traffic accident were analyzed based on the accident data and segment speed data of Beijing. Then, a congestion judgment model based on speed difference was established, that on the base of traffic accident information, traffic flow and speed data of accident sections. The constraint conditions of its spatial and temporal dimensions are limited. The spatial and temporal scope of congestion caused by accident was quantitatively described, and the effect verification was conducted based on the simulation data and the real accident data of Beijing. The results show that this method can effectively describe the spatial and temporal distribution characteristics of traffic congestion caused by traffic accidents. This model is of great significance to clarify the spatial and temporal distribution characteristics of traffic congestion caused by accidents, to predict traffic congestion caused by accidents, and to formulate policies to alleviate traffic congestion.