High Quality Content by WIKIPEDIA articles! U.S. Route 40 Alternate (Alt US 40) is the United States highway designation for a former segment of U.S. Route 40 (US 40) through Garrett and Allegany Counties in Maryland. The highway begins at US 40 near exit 14 on Interstate 68 and runs 31.80 miles (51.18 km) eastward to Cumberland, where it ends at exit 44 on Interstate 68.Alt US 40 is maintained by the Maryland State Highway Administration (MDSHA).