LANSING — Volunteers will fan out across lower Michigan to give state highway roadsides their annual spring cleaning beginning Saturday as groups in the Michigan Department of Transportation Adopt-A-Highway program pick up litter from today to May 1.

The first AAH pickup for the Upper Peninsula will be later, from May 7 to May 15, when spring has had more time to set in.

“We want to acknowledge the valuable service these thousands of Adopt-A-Highway volunteers provide each year keeping our roadsides clean,” state Transportation Director Paul C. Ajegba said in a statement. “Their commitment to their communities makes a huge difference across Michigan. We also remind motorists to keep an eye out for the volunteers and drive cautiously during the pickup periods.”

The AAH program began in Michigan in 1990. Today, around 2,900 groups have adopted more than 6,000 miles of state highway. In a typical year, these volunteers collect 60,000 to 70,000 bags of trash annually, an estimated $5 million value for the state.

Volunteers pick up litter three times each year. Statewide, there will be a summer pickup from July 16 to 24 and a fall pickup from Sept. 24 to Oct. 2.

AAH groups wear high-visibility, yellow-green safety vests required by federal regulations when working within a highway right of way. MDOT provides free vests and trash bags, and arranges to haul away the trash.

Volunteers include members of various civic groups, businesses and families. Crew members have to be at least 12 years old, and each group must number at least three people.

Sections of highway are still available for adoption. Groups are asked to adopt a section for at least two years. AAH signs bearing a group’s name are posted along the stretch of adopted highway. There is no fee to participate.

Several landfills in southwestern Michigan are also chipping in to help the AAH program.

Westside Landfill in St. Joseph County, C&C Landfill in Calhoun County, Orchard Hill Landfill in Berrien County, Southeast Berrien County Landfill near Niles, and Republic Services Gembrit Circle Transfer Station in Kalamazoo have all agreed to accept trash generated by the three annual AAH pickups at no charge. In exchange, these businesses receive a sign recognizing their support.