Efficient determination of vehicle emission factors by fuel use category using on-road measurements: downward trends on Los Angeles freight corridor I-710.
Efficient determination of vehicle emission factors by fuel use category using on-road measurements: downward trends on Los Angeles freight corridor I-710.
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DOI：
10.5194/acp-13-347-2013
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发表时间：
2013-01-11
影响因子：
6.3
通讯作者：
Sioutas C
中科院分区：
文献类型：
--
作者：
Hudda N;Fruin S;Delfino RJ;Sioutas C
为了评估车辆排放法规的成功，需要车队范围内的平均排放量以及高排放源排放量的趋势，但是利用底盘测功机或隧道研究来捕获车辆排放因子（EF）的全部分布具有挑战性，并且遥感研究不能评估颗粒化合物。我们开发了一种替代方法，该方法将来自移动的平台的实时道路污染物测量与实时交通数据联系起来，并允许有效计算轻型汽油动力车辆（LDG）和重型柴油动力车辆（HDD）的EF的平均值和分布。这是加州第一项在多条高速公路上全方位真实驾驶条件下报告EF的研究。船队平均LDG EFs与最近的研究一致，并且比观测到的HDD EFs低一个数量级。HDD EF反映了最近在洛杉矶/加州发生的柴油排放相对快速的下降，并且在I-710上，用于货物运输的主要路线和额外的卡车车队周转激励的焦点，HDD EF通常低于其他高速公路。当高速公路排放率（ER）被量化为产品的EF和车辆行驶里程（VMT）每一次每英里的高速公路，尽管在HDD分数高速公路之间的两到三倍的差异，ER被发现是一般相似的幅度。在低HDD部分高速公路上，更高的LDG VMT在很大程度上抵消了差异。因此，具有最高HDD分数的高速公路是洛杉矶的总排放的显著更差的来源的传统假设可能不再是正确的。
To evaluate the success of vehicle emissions regulations, trends in both fleet-wide average emissions as well as high-emitter emissions are needed, but it is challenging to capture the full spread of vehicle emission factors (EFs) with chassis dynamometer or tunnel studies, and remote sensing studies cannot evaluate particulate compounds. We developed an alternative method that links real-time on-road pollutant measurements from a mobile platform with real-time traffic data, and allows efficient calculation of both the average and the spread of EFs for light-duty gasoline-powered vehicles (LDG) and heavy-duty diesel-powered vehicles (HDD). This is the first study in California to report EFs under a full range of real-world driving conditions on multiple freeways. Fleet average LDG EFs were in agreement with most recent studies and an order of magnitude lower than observed HDD EFs. HDD EFs reflected the relatively rapid decreases in diesel emissions that have recently occurred in Los Angeles/California, and on I-710, a primary route used for goods movement and a focus of additional truck fleet turnover incentives, HDD EFs were often lower than on other freeways. When freeway emission rates (ER) were quantified as the product of EF and vehicle miles traveled (VMT) per time per mile of freeway, despite a twoto three-fold difference in HDD fractions between freeways, ERs were found to be generally similar in magnitude. Higher LDG VMT on low HDD fraction freeways largely offset the difference. Therefore, the conventional assumption that free ways with the highest HDD fractions are significantly worse sources of total emissions in Los Angeles may no longer be true.