Modeling Vehicle Fuel Consumption and Emissions at Signalized Intersection Approaches:
Assessing Available Tools and Research Needs
Understanding and quantifying the relationship between vehicle fuel use and emissions and its trajectory throughout signalized intersection approaches is an important step toward quantifying the environmental benefits of different signal improvement projects or mitigation measures. The objectives of this exploratory research project are to relate traffic flow parameters in signalized intersection approaches to real-world vehicle fuel use and pollution emissions, review and validate the output of existing modeling tools, and identify research needs in this area that could be a focus of future NIATT research efforts.
After a complete literature search to determine the current state-of-the-art, a first-order model of the effect of traffic control on fuel use will be created. The rates of fuel use will be evaluated during each "mode" of travel throughout the intersection approach: acceleration, deceleration, cruise, and idle. The relationship between vehicle fuel consumption and commonly used traffic measures, such as control delay at signalized intersections, will be investigated. Based on the results of the preliminary model, later plans call for the collection of real-time fuel use and vehicle emissions data through the use of a portable, On-board Emission Measurement unit (OEM 2100TM). The OEM 2100 allows real-time, field data collection of second-by-second measurement of tailpipe emissions (i.e., CO, HC, and NO) and engine operations (i.e., speed and engine rpm). Data from this research can be used to verify, calibrate, and validate values obtained from the newly released EPA MOVES 2010 model as well as other modeling tools available. The output of the analysis will help identify data and research needed to improve the accuracy of vehicle fuel consumption and emissions predictions. The output of the project will provide practitioners throughout the nation with guidelines on how to use the MOVES model as well as other microscopic traffic modeling tools to assess the potential reduction in fuel use and emissions that could result from traffic signal improvement projects.