Maryland Route 408

Maryland Route 408 (MD 408) is a state highway in the U.S. state of Maryland. Known as Mount Zion-Marlboro Road, the highway runs 5.62 miles (9.04 km) from MD 4 at Waysons Corner east to MD 2 and MD 422 in Lothian. MD 408 is the old alignment of MD 4 in southern Anne Arundel County. The highway was constructed in the late 1910s and became the easternmost part of MD 4 in 1927. The highway received its present designation in the mid-1960s when MD 4 was rerouted south into Calvert County. MD 408's western end was relocated when MD 4 was upgraded to a freeway through Waysons Corner in the early 1990s. MD 408 was also applied to the old sections of MD 4 between Andrews Air Force Base and Upper Marlboro in Prince George's County. The number was assigned after the MD 4 freeway was completed in the mid-1960s. The Prince George's County portions of MD 408 were transferred to county maintenance in the late 1970s except the section through Upper Marlboro, which became MD 725.