Transportation is intertwined with air quality. Some 70 percent of summer smog is caused by emissions from vehicles. On-road vehicles also contribute substantial amounts of fine particulate pollution.

Yolo-Solano AQMD does not have direct jurisdiction over on-road mobile sources – that authority lies with the California Air Resources Board and the U.S. Environmental Protection Agency. Yet the Yolo-Solano AQMD cannot meet air quality health standards without substantial reductions in emissions from mobile sources.

As such, the District has two strategies for reducing transportation-related emissions: incentives and advocacy.


The District funds clean transportation projects through its annual Clean Air Funds grant program. The application period typically opens in late January.

The District is working with school districts on its Clean School Bus Program. Funds from DMV registrations are being leveraged to clean up local school bus fleets.


The District encourages residents to use these clean transportation modes to help protect our clean air while moving around the region.