July 22, 2021

Proposed Amendments to the Exhaust Emissions Standards and Test Procedures for 2024

On-road heavy-duty vehicles contribute significantly to California’s poor air quality with elevated levels of ozone and particulate matter (PM or PM2.5). Statewide, about 12 million Californians live in communities that exceed the National Ambient Air Quality Standards for ozone and PM2.5. Exposure to PM2.5 and ozone are associated with an increased risk of premature mortality, which has been estimated to contribute to 7,500 premature deaths each year in California.  

Two areas of the state with the most critical air quality challenges are the South Coast and the San Joaquin Valley air basins. These regions are the only two areas in the nation with an “Extreme” classification for nonattainment with the federal ozone standard, and also experience some of the nation’s highest PM levels. Achieving federal air quality standards in these regions, as well as across the state, will provide essential public health protection by reducing hospitalizations for heart and lung-related causes, decreasing emergency room visits, and reducing incidences of asthma. 

REMI Policy Insight Plus provides year-by-year estimates of the total impacts of the Proposed Regulation, pursuant to the requirements of SB 617 and the California Department of Finance.97,98 CARB uses the REMI single-region, 160-sector model with the model reference case adjusted to reflect the Department of Finance confirming forecasts. These forecasts include California population figures dated May 2019, U.S. real gross domestic product forecast, and civilian employment growth numbers dated April 2019. 

State of California Air Resources Board – Proposed Heavy-Duty Engine and Vehicle Omnibus Regulation and Associated Amendments [Full PDF]