Quantifying the Impact of Truck Only Lanes on Vehicular Emissions on a Limited-Access Highway

Author

Edward Chee Tang, California Polytechnic State University, San Luis ObispoFollow

DOI: https://doi.org/10.15368/theses.2017.33
Available at: https://digitalcommons.calpoly.edu/theses/1743

Date of Award

6-2017

Degree Name

MS in Civil and Environmental Engineering

Department/Program

Civil and Environmental Engineering

Advisor

Anurag Pande

Abstract

This thesis seeks to estimate CO₂ emissions on a portion of the U.S. 101 highway in San Luis Obispo County before and after construction of a truck only lane on the Cuesta Grade. Towards that aim, the microsimulation software, VISSIM, was used in conjunction with the Environmental Protection Agency’s emissions model, MOVES. The microsimulation model was calibrated and validated against historical and present traffic volumes obtained from Caltrans with good results using several validation measures. It was found that CO₂ emissions did decrease between 1998 and 2012 (pre and post lane addition), but this effect was shown to be different for the northbound (uphill) and southbound (downhill) directions. It was shown that the truck lane in the northbound (uphill) direction had a 9.5% decrease in volume with 10.7% decrease in emissions, and the southbound (downhill) direction had a 20.3% increase in volume but 7.4% decrease in emissions. For the northbound (uphill) direction, emissions seemed to correlate more closely with volumes, while the southbound (downhill) direction was less sensitive to these changes.