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 filters due to aging, 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 participate 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 children's 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 particulate matter (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 children’s exposure to vehicle-related pollutants during their school bus trips. Under the Truck and Bus Regulation, all school buses are required to have a particulate matter 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 at our schools and in our neighborhoods. CARB has been working to provide financial incentives for school districts to replace older diesel-fueled school buses for nearly twenty years, starting with the Lower-Emission School Bus Program in 2001, with the goal of reducing children’s exposure to harmful diesel exhaust.

Additionally, funding that supports some or all of the cost of a new, clean technology vehicle, incentives help to drive the development of newer and cleaner technologies by speeding up their adoption by school bus fleet owners.

And, this project implements the recommendation from the SB 350 Final Guidance Document to secure commitments from school bus fleet owners to purchase zero-emission and near-zero emission school buses.

Project Funding/Allocations/History

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 $1,759,787 of Federal funds towards the replacement of 20 old diesel school buses, co-funded with Rural School Bus Pilot Project funds.

Recent Project/Policy Changes

This pilot project was included in the FY 2015-16 Funding Plan with a $5 million allocation with the anticipation that additional funds would be allocated in future years. However, CARB was not able to fund this pilot project because of the smaller than anticipated FY 2015-16 Low Carbon Transportation budget appropriation.

For FY 2016-17, CARB allocated $10 million for this project. The overwhelming response during the project’s application period for the FY 2016-17 funding cycle demonstrated a strong interest by California school districts to participate in the project and utilize zero-emission school buses. In January 2018, CARB redirected an additional $5 million to the FY 2016-17 grant with NCUAQMD.

$10 million was allocated to continue this project for FY 2017-18. No changes to project criteria were proposed. A new solicitation was held in June 2018 receiving nearly 600 old school bus applications, with requested funds totaling approximately $185 million. CARB reallocated $15 million of FY 2017-18 reserve funding for a total of $25 million to meet the strong demand for cleaner school buses.

In development of the FY 2018-19 Funding Plan, $15 million was allocated to continue to fund projects from the 2018 solicitation and ranked list, with no changes to project criteria.

The FY 2019-20 Funding Plan proposed allocating $4.45 million that could fund approximately 13 additional new school buses. Due to reductions directed by the Department of Financing per the Budget Act of 2019 associated with lower fourth quarter Cap-and-Trade auction proceeds, resulted in a reduction to project funding allocation. Ultimately, NCUAQMD was awarded $3 million in a grant agreement to select from the 2018 solicitation pool of old school bus applications. Staff proposed two changes to the program, starting with FY 2019-20 funds. The first change required dismantling of all old school buses replaced by this program. The second change required checking the old school buses’ compliance status with the Truck and Bus Regulation as part of the award amount determination. School buses are regulated under 13 CCR 2025(k), the school-bus specific section of the Truck and Bus Regulation which requires that any diesel school bus over 14,000 lbs. gross vehicle weight rating, either have a diesel particulate filter (either original from the factory or as an add-on retrofit), or operate less than 1,000 miles per calendar year. School buses (individually, not as a fleet) that do not meet this requirement receive a lower funding amount. This change ensured that those school districts that had not complied with the regulations are not prioritized over fleets that are in compliance.

After several years of successful implementation, in FY 2021-22 the Rural School Bus Pilot Project transitioned from a pilot to a full-scale project. The FY 2021-22 State Budget included funding for a multi-year commitment to replacement of older, internal combustion engine school buses with zero-emission school buses. CARB received a total appropriation of $265 million with $130 million available for the first year of the incentive program. The Public School Bus Set-Aside funding was implemented through the Clean Truck and Bus Voucher Incentive Project (HVIP). Some Rural School Bus Pilot Project requirements migrated to the HVIP set-aside funding, including prioritization of rural areas and scrappage of an older school bus.