U.S. Route 40 Alternate (Alt US 40) is the U.S. 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).
The highway is known as National Pike to reflect the fact that it follows the original alignment of the National Road. As the route of the historic National Road, there are many historic sites along Alt US 40, including the Casselman Bridge in Grantsville and the last remaining National Road toll gate house in Maryland, located in LaVale.
When the National Freeway was built in western Maryland paralleling the old National Road, parts of U.S. Route 40 were bypassed. The part of the bypassed road between Keyser's Ridge and Cumberland became Alt US 40, and other bypassed sections east of Cumberland became Maryland Route 144 and U.S. Route 40 Scenic. Although Alt US 40 has diminished in importance from its original status as the National Road due to the construction of Interstate 68, it remains an important route for local traffic and serves as the Main Streets of Grantsville and Frostburg.
Alt US 40 runs from Keyser's Ridge to Cumberland, following part of the route of the National Road through some of Maryland's most mountainous terrain in Garrett and Allegany counties.
Alt US 40 branches from US 40 near exit 14 on Interstate 68 at Keysers Ridge. It runs parallel to Interstate 68 through northern Garrett County as a two-lane road with truck lanes on some uphill sections. The annual average daily traffic (AADT)—that is, the number of cars that use the road per day, averaged over the course of one year—is 1,831 at the western end of Alt US 40. For comparison, the parallel section of Interstate 68 has an AADT of 14,271. Alt US 40 passes through some of the most mountainous terrain in Maryland. The route runs perpendicular to the mountain ridges in Garrett County, and as a result much of the section of the road in Garrett County runs uphill or downhill. The first mountain encountered by the highway east of Keysers Ridge is Negro Mountain. The road passes over the mountain at an elevation of 3,075 feet (937 m), which is the highest point