California Air Resources Board

Project Goals

This project encourages the turnover of the California school bus fleet to lower carbon transportation choices. Older diesel school buses are more polluting with higher deterioration of the engines and particulate matter (PM) filters due to aging, thereby exposing children, a sensitive population group, to more emissions. Turning over the oldest school buses also has the added benefits of supporting California’s air quality, climate change, and petroleum reduction goals. Rural and low-income communities actively participated in the acceleration for the introduction and deployment of zero-emission technologies through the Rural School Bus Pilot Project.

Guiding Legislation/Policy Drivers

This project is driven by three main goals: to reduce children’s exposure to harmful pollutants, to speed adoption of zero-emission technologies, and to fulfill recommendations set forth in CARB’s SB 350 Barriers Report and Final Guidance Document.

CARB aims to reduce childrens' exposure to harmful pollutants through regulatory requirements and incentive funding for new, cleaner school buses. The Children's Health Study, initiated in 1992, confirmed that exposure to high concentrations of PM reduces lung development, has immediate adverse health effects, and with continued exposure, has lasting adverse health effects later in life. The Children's School Bus Exposure Study, conducted in 2003, further demonstrated that the school bus's own exhaust greatly increases children’s exposure, and the oldest school buses have the highest rates of in-vehicle exposure. CARB is committed to prioritizing the most sensitive population groups and aims to reduce health risks through regulatory action and incentive programs for new clean technology.

CARB has taken several actions to reduce childrens' exposure to vehicle-related pollutants during their school bus trips. Under the Truck and Bus Regulation, all school buses are required to have a PM exhaust filter; either original manufacturer equipment or retrofit, or they must operate less than one thousand miles per calendar year. School buses of any fuel type are restricted from school bus idling at or near public or private schools, drivers are required to turn off engines immediately upon arrival at a school and restart no more than thirty seconds before departure. Finally, school bus fleets must regularly test for excessive smoke.

Along with regulatory requirements, financial incentives are a major part of CARB’s efforts to ensure clean school buses are operating for our students and in our neighborhoods. CARB has been working to provide financial incentives for school districts to replace older diesel-fueled school buses for over twenty years, starting with the Lower-Emission School Bus Program in 2001, with the goal of reducing children’s exposure to harmful diesel exhaust.

Project Funding

Greenhouse Gas Reduction Funds:

• FY 2016-17 $15,000,000
• FY 2017-18 $25,000,000
• FY 2018-19 $18,550,000
• FY 2019-20 $  3,000,000

The U.S. EPA’s Diesel Emission Reduction Act State grants provided an additional $1,115,698 of Federal funds towards the replacement of 14 old diesel school buses, co-funded with Rural School Bus Pilot Project and Carl Moyer funds.