EFFECTS OF HEAVY-DUTY DIESEL VEHICLE IDLING EMISSIONS ON AMBIENT AIR QUALITY AT A TRUCK STOP - MEASUREMENTS AND MODELING OF NOX AND PM2.5 CONCENTRATIONS

摘要

Department of Transportation (DOT) requires truck drivers to rest for 10 hours after every 14 hours of driving. During this time and while waiting for loading and unloading of their trucks, truck drivers idle their engine to provide heat or air conditioning for the cab and sleeping compartment, keep the engine warm during cold climate, and provide electrical power for their onboard appliances. At large truck stops, 200 or more trucks may be idling at the same time. At these truck stops idling emissions can significantly contribute to the concentrations of NOx and PM2.5 pollutants in the ambient air in the vicinity of the truck stop. In this study monitoring of ambient air at a large truck stop was performed between mid December 2003 and August 2004. Concentrations of PM2.5 and NOx were measured continuously at two locations. Computer modeling was also performed using EPA's ISCST3 model to predict ambient concentrations of PM2.5 and NOx at the truck stop. The monitored concentrations of PM2.5, and NOx were then compared to the predicted values in an effort to verify and calibrate the model. The model can be used to predict the concentrations of pollutants from idling trucks at other truck stops, and rest areas and to identify the extent of PM2.5 "hot-spot" areas near truck stops where National Ambient Air Quality Standards may be exceeded.