Analysis of Emissions at Congested and Uncongested Intersections with Motor Vehicle Emission Simulation 2010

The motor vehicle emission simulator (MOVES) modeling software of the U.S. Environmental Protection Agency enables researchers and practitioners to model vehicle emissions at the project level. With this tool, agencies can identify and evaluate the effectiveness of local traffic control strategies to reduce emissions at project hot spots, such as congested intersections. This study analyzes vehicle emissions at congested and uncongested signalized intersections under three traffic intersection scenarios, ranging from Level of Service (LOS) B to LOS E. Emissions are much less sensitive to congestion than control delay. A shift in operation from LOS E to LOS B reduced per vehicle nitrogen oxide emissions by 15% and particulate matter emissions by 17%, while control delay decreased by 40%. The largest sources of emissions were cruising and acceleration; they accounted for more than 80% of total emissions under all scenarios. Idling accounted for less than 18% of all intersection emissions. This analysis calculates emissions with a time-in-mode methodology that combines emission factors for each activity mode (i.e., acceleration, deceleration, cruise, idle) with a calculation of the total vehicle time spent in that mode. This approach demonstrates the contribution of each activity mode to intersection emissions and suggests opportunities for control strategies with the potential to affect intersection emissions. The streamlined methodology may be a helpful tool for agencies that are interested in analyzing project-level emissions and control strategies, but lack staff resources or expertise for microsimulation-based scenario analysis.