基于车辆身份检测数据的单车排放轨迹研究

为实现单车层面的动态排放轨迹追踪，基于电警式卡口产生的逐秒过车记录数据建立了车辆排放轨迹计算方法，通过提取动态轨迹中的运行参数及机动车保有量数据库中的技术参数，并结合排放模型计算了2018年5月10日~6月9日安徽宣城市中心城区123条路段上共133，906辆车的44，672，343条轨迹的排放数据.研究结果显示，出租车是CO的重要排放来源且交通兴趣点附近路段排放强度较高；公交车和重型货车是NO_x的重要排放来源，公交车工作日NO_x排放总量达1.3kg，约为重型货车的7.5倍，且路线固定、排放分布随发车班次周期循环；轻型货车排放路线多围绕货运需求且多为昼间行驶，而重型货车多选择凌晨出行；通勤类私家车工作日昼出夜归，路线固定且往返过程各污染物排放量均较稳定.对于全路网，CO、VOCs的高排放强度区域多集中于中心路网，NO_x、PM则多分布于外围路网.

Research on vehicle emission trajectory based on vehicle identification data

To track the dynamic emission trajectory of an individual vehicle, a method for calculating the emission trajectory was established based on the second by second vehicle passing records from Electronic Police system. Taking the urban center of Xuancheng, Anhui Province as the study area, which has 123 road links, 44,672,343emission trajectories of 133,906 vehicles from May 10 to June 9 in 2018 were calculated using the operational parameters from the reconstructed trajectories, the technical parameters from the motor vehicle database, as well as the emission factors from International Vehicle Emission Model. The results show that, taxi contributed more to CO emissions and the emission intensity was high on the road links near points of interest. Bus and heavy-duty truck were the main sources of NO_x emissions. The total amount of NO_x emissions from bus on workday was nearly 1.3kg, which was about 7.5 times higher than that of the heavy-duty truck. For bus, the bus route was fixed and the temporal-spatial distribution of emissions showed a certain periodicity according to the bus frequency. The trajectory of light-duty truck was mainly determined by freight demand, which often travels during the day. On the other hand, the heavy-duty truck was more inclined to travel in the early morning. The commuting private car made regular travel during workdays, hence the pollutant emissions were relatively stable in the round-trip process. For the whole road network, the high emission intensity areas of CO and VOCs were concentrated in the central road network, while for NO_x and PM, they were mainly distributed in the peripheral road network.