Development of a Comprehensive Modal Emissions Model

In August 1995, the College of Engineering-Center for Environmental Research and Technology (CECERT)at the University of California-Riverside along with researchers from the University of Michiganand Lawrence Berkeley National Laboratory, began a four-year research project to develop aComprehensive Modal Emissions Model (CMEM), sponsored by the National Cooperative HighwayResearch Program (NCHRP, Project 25-11). The overall objective of the research project was to developand verify a modal emissions model that accurately reflects Light-Duty Vehicle (LDV, i.e., cars andsmall trucks) emissions produced as a function of the vehicle’s operating mode. The model iscomprehensive in the sense that it is able to predict emissions for a wide variety of LDVs in variousstates of condition (e.g., properly functioning, deteriorated, malfunctioning). The model is now completeand capable of predicting second-by-second tailpipe emissions and fuel consumption for a wide range ofvehicle/technology categories. In creating CMEM, over 350 vehicles were extensively tested on a chassisdynamometer, where second-by-second measurements were made of both engine-out and tailpipeemissions of carbon monoxide, hydrocarbons, oxides of nitrogen, and carbon dioxide. CMEM itself runson a personal computer or on a UNIX workstation. The model and the emissions database are bothavailable on a CD.