Estimation of the Impact of Electronic Toll Collection on Air Pollution Levels Using Microscopic Simulation Model of a Large- Scale Transportation Network

This paper presents a microscopic simulation based estimation of the spatio-temporal change in air pollution levels as a result of electronic toll collection (ETC) deployment in New Jersey Turnpike (NJTPK), a large-scale traffic network. Other important features of this paper are the (1) disaggregate spatial estimation and analysis of the emissions instead of aggregate system-wide estimations, (2) the use of a vehicle-based and well-calibrated traffic simulation model of NJTPK network in PARAMICS microscopic simulation software to perform this disaggregate emission estimation, (3) the use of a unique and realistic toll plaza model with a complete mainline model to capture complex mainline-toll plaza interactions, and (4) the study of short and long term impacts of ETC systems. The simulation model is loaded with a recent network specific dataset, which includes origin-destination demand data for 1999 (before ETC deployment) and for 2005 (six years after ETC deployment) and toll plaza service times obtained from toll plaza videotapes. MOBILE 6.2 mobile source emission model developed by the Environmental Protection Agency is integrated in PARAMICS. At each time step of the simulation air pollution levels, namely CO, HC, NO x and PM10 emissions are calculated for each vehicle type based on their speeds. The simulation network is used to estimate not only the change in system-wide air pollution levels but also the spatial changes throughout the system. Results show that ETC deployment reduces the overall network air pollution level in the short term; however, in the long term its benefits are not sufficient enough to compensate the air pollution increase on the mainline because of annual traffic growth.