2. New Features

EMFAC2025 introduces several new features to enhance the accuracy of on-road mobile source emissions inventories in California. Section 2.1 describes the new module for estimating emissions from light-duty vehicles aged 45 years and older, which contribute disproportionately to total emissions despite representing a small fraction of the total fleet. Section 2.2 focuses on the update on high-speed driving of light-duty vehicles, which incorporates new activity and speed correction factors to better model emissions in speed bins from 70 to 90 mph. Section 2.3 details the split of light heavy-duty trucks (LHD1 and LHD2) into public and other categories to better reflect the Advanced Clean Fleets regulation requirements for public fleets.