The Maryland Department Of Transportation State Highway Administration (MDOT SHA) Adopt-A-Highway Program lets community groups show their state pride and keep the Free State litter-free. Keeping our roadways free from litter and debris improves the health of our environment. It enhances the experience of driving in Maryland – for both residents and visitors. Since the Adopt-A-Highway Program started in 1989, MDOT SHA has partnered with more than 120,000 Marylanders who have cleaned over 15,000 miles of roadside.