Assessing Emissions Contribution of Intercity Trucking

The contribution of intercity trucking to air pollution in a given region is readily recognized as significant by transportation and air quality planners. Other than emissions standards for newly sold trucks, neither the air quality nor the transportation planning communities has focused on implementing control strategies that directly mitigate emissions from intercity trucking. As nonattainment areas strive to comply with the National Ambient Air Quality Standards, the potential emission reduction benefits of truck-related control measures must be evaluated to ensure that all sources of emissions are considered in the planning processes. However, little is known about the contribution of intercity trucking to emissions inventories in regions across the country, particularly since the Environmental Protection Agency's MOBILE emissions factor model is not well-suited for this purpose. The incorporation of intercity trucking in emission inventory estimates is reviewed, and a methodology by which intercity trucking emissions can be easily isolated using information documented in state implementation plans (SIPs) is developed. Using SIP data for a select number of metropolitan areas and the Truck Inventory and Use Survey (TIUS), the emissions contributions of city-to-city truck transport and drayage operations are assessed. Furthermore, the contribution of intercity trucking to emission reductions in areas across the country is determined using information reported in 15 percent volatile organic compound reduction plans.