SLO County Adopt-a-Road is a program in which volunteers (groups or individuals) do trash removal along county roads. It is coordinated by the county Public Works Department.

Website: https://www.slocounty.ca.gov/Departments/Public-Works/Services/Adopt-A-Road.aspx

See also: "Road warriors: You've seen the signs, but what is adopting a road or highway all about?" New Times January 7, 2015