A COMPREHENSIVE EXAMINATION OF HEAVY VEHICLE EMISSIONS FACTORS

This report summarizes the findings from reviewing the literature on several topics that are related to heavy vehicle emissions including engine and fuel types, vehicle technologies that can be used to reduce or mitigate vehicle emissions, the factors that affect vehicle emissions, vehicle emissions modeling, and current and future policy requiring accurate accounting of heavy vehicle emissions. The pollutants present in diesel exhaust are known to have undesirable effects on both human health and the environment. There are many engine and fuel alternatives for current and prospective vehicle owners to consider that have differing effects on a vehicle’s pollutant output. In addition, new technologies, such as diesel particulate filters, auxiliary power units, and selective catalytic reduction, are being used in the production of new vehicles, and can often be installed on used vehicles, to reduce emissions and/or improve fuel economy. Accurate heavy vehicle emissions modeling is important in forming policies designed to reduce pollutants from heavy vehicle operation at both the vehicle and regional level. Such policies can include cap-and-trade schemes, carbon taxing, and road user charging. All of these policy types have been implemented in the European Union to varying degrees, but only some have been implemented in the United States. However, all of these are now being considered in the U.S., and could be implemented in the future.