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CALMOB6: A Fuel Economy and Emissions Tool for Transportation Planners


This paper describes a Matlab-based emissions and fuel consumption model customized for the City of Edmonton. The City needs a tool to quantify the environmental effects of planned transportation control and urban development measures. The CALMOB6 program calculates emissions and fuel consumption effects of proposed developments or regulations before they are implemented, aiding in selecting the most suitable project. The program handles the criteria air pollutants (carbon monoxide, nitrogen oxides, hydrocarbons and particulates) and greenhouse gas emissions (carbon dioxide and methane), as well as fuel consumption rates for vehicles operating in an urban region. CALMOB6 uses the output of urban travel forecasting models (such as EMME/2 or VISSIM) to describe vehicle movements. With this as a base, the model develops a second-by-second speed trace for each vehicle type in a particular traffic situation based on both the traffic model output and local parameters such as road grade and ambient weather conditions. The vehicle speed trace matches the specified average speed while incorporating stops, idling times, permissible speeds and realistic acceleration rates for each vehicle class. A class-specific vehicle dynamic model is applied to this speed trace to calculate a tractive power trace which is then applied to emissions and fuel consumption functions developed at the University of Alberta. The emissions functions for each vehicle class are calibrated against emission rates embodied in the US EPA’s MOBILE6, (hence CALMOB6) as a standard for vehicles driving EPA test cycles. Similarly, fuel consumption is calibrated against past fleet fuel economy and extended with future fuel economy trends obtained from technical literature.

Conference Paper Details

Session title:
Transportation planning