Developing A Microscopic Transportation Emissions Model To Estimate Carbon Dioxide Emissions On Limited-Access Highways


This paper presents an optimal design approach for developing a microscopic transportation emissions model (Micro-TEM). The main purpose of Micro-TEM is to achieve an acceptable degree of accuracy as a surrogate model for predicting transportation emissions of carbon dioxide (CO2) on limited-access highways as an alternative to using a traffic model and then integrating those results into an emissions model. Key parameters related to traffic (volume, truck percentage, speed limits), geometry (road grade), and environment (temperature) were selected for detailed evaluation. Estimating vehicle emissions on the basis of second-by-second vehicle operation created the opportunity to integrate a microscopic traffic simulation model, VISSIM, with the latest U.S. Environmental Protection Agency mobile source emissions model, the Motor Vehicle Emission Simulator (MOVES), for higher precision and accuracy. The VISSIM-MOVES integration software, VIMIS, was developed to facilitate running a multilevel factorial experiment on a test-bed prototype of an urban section of I-4, a limited-access highway in Orlando, Florida. The analysis identified the optimal settings for CO2 emissions reduction on the basis of two main parameters, traffic volume and speed. Volume correlation with CO2 emissions rates revealed an exponentially decaying function toward a limiting value expressed in the freeway capacity. Moreover, at speeds between 55 and 60 mph there was a significant reduction in the emissions rate, yet up to 90% of the freeway capacity was maintained. The results demonstrated that active speed management has a significant impact on CO2 emissions provided that a detailed and microscopic analysis of vehicle acceleration and deceleration has been conducted. This approach can provide environmental decision makers with practical guidelines for their decisions on environmental transport policies.

Publication Date


Publication Title

Transportation Research Record



Number of Pages


Document Type


Personal Identifier


DOI Link


Socpus ID

84907558051 (Scopus)

Source API URL


This document is currently not available here.