基于PM2.5减排的道路缩减下的交通流动力学建模及优化策略研究

Vehicle exhaust presents one of the dominant sources of PM2.5 in urban areas, and enhancing the control of vehicle emission on road will definitely help alleviate the pollution level. Concerning all processes related to vehicle emission, traffic congestion has been repeatedly identified as a major cause of deterioration in urban air quality. The road reduction section is the vulnerability spot to road network as well as the high-incidence section of traffic congestion. Hence, it is necessary to carry out experimental and theoretical research on the evolution process of phase transition of traffic flow at reduction section, explore the effect of phase transition of the traffic flow at the upstream and downstream of the reduction area on its spatial-temporal distribution of PM2.5 emissions, and provide strategy for PM2.5 reduction through optimization of traffic flow. This project aims to characterize the dynamic road environments and driving behavior by collecting data of traffic flow and PM2.5 emission at set points of multi-sections, to perform the mobile measurement on multi-vehicles, to propose a kinetic model of PM2.5 emission for road reduction by combining emission factor, to investigate the self-organization phenomenon of traffic flow and related spatial-temporal distributions of PM2.5 emission at the upstream and downstream of different reduction section, and also to provide the guiding information for vehicular PM2.5 control. Research outputs are expected to provide a theoretical and practical basis for traffic flow optimization and PM2.5 emission reduction.

机动车尾气是我国城市PM2.5的主要来源，加大对机动车排放的控制力度,有助于缓解颗粒污染的严重程度。在所有与交通排放相关的过程中，交通拥堵被认为是造成城市空气质量恶化的主要诱因。因此，发生道路缩减的路段作为拥堵的高发区域，有必要针对其交通流动相变的演化过程开展实验和理论研究、探讨缩减路段上、下游交通流相变对其PM2.5排放时空分布的影响，指导优化交通流动，探索通过交通流动的优化实现PM2.5减排的控制策略。本项目采用多缩减区定点与多车辆跟车相结合的实验方式，通过缩减区交通实验和PM2.5监测，将外部道路环境和驾驶者行为等影响因素参数化，结合排放因子，构建道路缩减下的PM2.5排放的动力学模型研究，据此研究不同缩减区的上、下游的交通自组织现象及PM2.5排放的时空分布规律。研究成果将为优化车辆交通效率和减少PM2.5排放提供科学的理论依据。

机动车尾气是我国城市PM2.5的主要来源，加大对机动车排放的控制力度,有助于缓解颗粒污染的严重程度。在所有与交通排放相关的过程中，交通拥堵被认为是造成城市空气质量恶化的主要诱因。本项目针对交通流动相变的演化过程开展理论和实验研究、探讨交通流相变对其PM2.5排放时空分布及交通设计对行人PM2.5暴露风险的影响，取得如下结论：.1)道路缩减对交通流相变及PM2.5排放时空分布的影响：通过大量的交通观测，从外部道路环境和驾驶者个人行为两个角度出发，模拟交通流相变前后，缩减区上、下游各路段的交通和污染工况，揭示道路设计因素和驾驶者行为对交通流相变及PM2.5排放时空分布的影响，提出针对道路缩减路况的机动车车流优化方法和PM2.5减排的策略。.2)城市行人颗粒物暴露的健康风险：通过交通污染实测和统计分析，对高架桥下拥堵路段的交叉路口颗粒物进行监测，探讨了冬季霾日与典型日不同粒子的扩散模式，对比了不同的交通信号周期设置对不同颗粒污染物水平变化和累积的影响，根据呼吸道颗粒沉淀模型，比较了地上人行横道和地下通道的空气污染暴露情况，为城市交叉口交通信号设计优化提供了新的参考方向。.本项目以问题为导向，以数据为驱动，深入探讨了交通与污染的相关问题。研究成果有助于揭示道路设计、交通污染排放及行人暴露之间的关系，为城市未来道路设计及打造适宜步行城市提供了科学的理论依据。