California Air Resources Board

The paved road dust category includes emissions of particulate matter (PM) from resuspended road surface materials that are entrained by vehicular travel on public and industrial paved roads. Entrained paved road dust, or fugitive dust, contributes to airborne PM emissions throughout California.

Changes in Methodology

There were several revisions in the paved road dust emission estimates for this update. These include:

1. Updated VMT data based on EMFAC2021 and the latest available activity data from the transportation planning agencies for the year 2023.
2. Updated fractions of vehicle miles traveled on Freeway, Major, Collector, and Local roads (travel fractions) to reflect 2022 Caltrans HPMS data.
3. Updated statewide average vehicle weights from 2.4 tons to 2.8 tons.
4. Updated average number of days per year that each county received 0.01 inches or more of precipitation during 2013-2023 using gridMET precipitation data.
5. Updated entrained road dust emissions for total PM, PM₁₀ and PM_2.5, by COABDIS.

The above changes decreased statewide PM₁₀ emissions for entrained paved road dust by about 3% from the previously published inventory estimates.