The Challenge
Detailed assessment of motor vehicle emissions that originate from transportation projects in California are needed for environmental documents that may be required under the California Environmental Quality Act (CEQA) and National Environmental Policy (NEPA). Federal transportation conformity requires certain projects of air quality concern to also undergo particulate matter hot-spot assessments, which requires detailed emissions analysis. The emissions assessment can be data intensive and time consuming and must use data from the California Air Resources Board (CARB) EMission FActors Model (EMFAC).
Our Solution
Spheros, in collaboration with faculty and researchers at U.C. Davis, developed an on-road motor vehicle emissions modeling tool, CT-EMFAC, to facilitate streamlined project-level emissions analyses. CT-EMFAC calculates on-road vehicle emissions of criteria pollutants, mobile source air toxics (MSATs), and greenhouse gases (GHGs), as well as fuel and electricity consumption. CT-EMFAC pairs emission factors from the California Air Resources Board’s (CARB) EMFAC motor vehicle emissions model with forecasted transportation activity (fleet mix, speed distribution, vehicle miles traveled) for multiple roadway links across multiple project scenarios.
Results +What makes this unique
CT-EMFAC facilitates a streamlined project-level emissions analysis framework for completing analyses that may be needed for CEQA, NEPA, and federal transportation conformity. CT-EMFAC’s user-friendly design facilitated widespread adoption within Caltrans. Spheros’ expertise in transportation air quality, data analysis, and tool development was key in developing a tailored solution to meet specific client needs and requirements.
Project Experts
