Business U.S. Route 40 is a 2-mile (3.2 km)-long loop through Redstone Township, Fayette County, Pennsylvania. While called the Brownsville business loop, it never officially enters the borough, but instead serves some of its associated commercial development. In 2009, a stretch of US 40 was relocated to provide better access to the new Pennsylvania Route 43 freeway. As a result of the protests of local businesses, the short bypassed stretch was signed.
This route was US 40's alignment through Uniontown prior to 1993, when a limited-access bypass around the southern edge of Uniontown was completed, causing US 40 to shift onto the expressway. The portion of the highway through the city center features a pair of one-way couplets along Main and Fayette Street. Trucks travelling westbound along Main Street are actually rerouted onto a street that is not state maintained, to avoid the narrow path in front of the Fayette County Courthouse.
The highway is known as Old 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.
U.S. Route 40 Scenic is a scenic route of U.S. Route 40 in the U.S. state of Maryland. US 40 Scenic is the old alignment of US 40 over Town Hill in eastern Allegany County and Sideling Hill in far western Washington County. The highway was originally constructed as part of the National Road in the early 19th century and paved as a modern road in the mid-1910s. US 40 was relocated over Sideling Hill in the early 1950s and over Town Hill in the mid-1960s. The US 40 Scenic designation was first applied to the old highway over Town Hill in 1965. Following the completion of Interstate 68 (I-68) at Sideling Hill, US 40 Scenic was extended east along old US 40's crossing of the mountain in the late 1980s. US 40 Scenic is one of only two U.S.-numbered scenic routes, the other being US 412 Scenic.
US 40 Alternate is the old alignment of US 40. The highway's path was blazed in the mid-18th century to connect the Hagerstown Valley and Shenandoah Valley with eastern Pennsylvania and central Maryland. In the early 19th century, US 40 Alternate's path was improved as part of a series of turnpikes to connect Baltimore with the eastern terminus of the National Road in Cumberland. The highway was improved as one of the original state roads in the early 1910s and designated US 40 in the late 1920s. Construction on a relocated US 40 between Hagerstown and Frederick with improved crossings of Catoctin Mountain and South Mountain began in the mid-1930s; the new highway was completed in the late 1940s. US 40 Alternate was assigned to the old route of US 40 in the early 1950s.
U.S. Route 40 Truck is a truck route of US 40 to route truck traffic away from Baltimore's downtown area, which mainline US 40 passes through. US 40's mainline also includes several low bridges, including the bridge which the Amtrak Northeast Corridor uses to cross the route. US 40 Truck diverges from US 40 at the intersection of US 40 (Edmondson Avenue) and Hilton Parkway, travelling north on the latter route to the western end of North Avenue. It runs east along the entire length of North Avenue, running concurrent with mainline US 1 from Fulton Avenue east. It turns north, along with US 1, onto Belair Road, and runs north until it meets Maryland Route 151 (Erdman Avenue). Here, it turns east again, following Erdman Avenue until it meets an interchange with mainline US 40 once again.