College of Transportation Engineering, Chang'an University, Xi'an 710064, China.
Key Laboratory of Transport Industry of Management, Control and Cycle Repair Technology for Traffic Network Facilities in Ecological Security Barrier Area, Xi'an 710064, China.
Int J Environ Res Public Health. 2022 May 27;19(11):6552. doi: 10.3390/ijerph19116552.
Due to stop-and-go events, bus stops are often treated as "hot spots" for air pollution. The design of bus stops should be optimized to reduce emissions and exposure for transit commuters. The objective of this study was to analyze the impact of bus stop platform types on vehicle emissions and individual pollution exposure. Second-by-second emissions data were first collected from one bus using a portable emission measurement system (PEMS). Microscopic traffic simulation was then used to estimate overall traffic emissions under six scenarios with different bus stop settings. Numerical simulation of pollutant dispersion was also conducted to calculate individual pollution exposure at bus stops. The results of PEMS tests showed no significant differences between bus emissions generated near two different types of stops. However, the effect of platform types on overall traffic emissions was revealed using traffic simulation. The results demonstrated that bus bays reduced the emissions of other heavy-duty vehicles. However, bus bays were not always effective during rush hours. The study also highlighted the importance of the location of bus stops, the number of bus lines, and the length of the platform, in addition to dynamic characteristics of traffic flows in the design of bus stop platforms. Bus stop platforms also affected individuals' exposure due to the changes in the pollutant flow field. The passenger's exposure at one bus stop was influenced by both the platform type and standing location. Results suggested that in a condition with a wind direction perpendicular to the bus stop shelter, the total exposure level to CO was lower at the bus bay stop if a passenger stood at the upstream of the station platform. However, the exposure was less at the downstream of the curbside bus stop.
由于停停走走的事件，公共汽车站经常被视为空气污染的“热点”。公共汽车站的设计应优化，以减少排放和过境通勤者的暴露。本研究的目的是分析公共汽车站台类型对车辆排放和个体污染暴露的影响。首先使用便携式排放测量系统 (PEMS) 从一辆公共汽车上收集逐秒排放数据。然后使用微观交通模拟来估计六种不同公共汽车站设置场景下的总体交通排放。还进行了污染物扩散的数值模拟，以计算公共汽车站的个体污染暴露。PEMS 测试的结果表明，在两种不同类型的车站附近产生的公共汽车排放之间没有显著差异。然而，使用交通模拟揭示了平台类型对总体交通排放的影响。结果表明，公共汽车停靠处减少了其他重型车辆的排放。然而，在高峰时段，公共汽车停靠处并不总是有效。该研究还强调了公共汽车站的位置、公交线路的数量和平台的长度，以及交通流的动态特性在公共汽车站台设计中的重要性。公共汽车站台也会影响个体的暴露，因为污染物流场发生了变化。一个公共汽车站的乘客暴露既受平台类型的影响，也受站立位置的影响。结果表明，在风向垂直于公共汽车站棚的情况下，如果乘客站在车站平台的上游，那么在公共汽车停靠处的总 CO 暴露水平较低。然而，在路边公共汽车站的下游，暴露量较少。
