It closely parallels Interstate 70 (I-70) from West Virginia until it reaches Washington, where it follows Jefferson Avenue and Maiden Street.

A short, limited-access highway in California and West Brownsville provides an approach to the Lane Bane Bridge across the Monongahela River.

It follows Braddock Road southeast of Uniontown, crossing the Youghiogheny River Lake on a bridge completed in 2006.

Route 40 passes through Scenery Hill and Beallsville before reaching PA 43/PA 88 at a full cloverleaf interchange in Centerville.

US 40 becomes a treacherous mountain highway for the next 5 miles (8 KM) featuring steep descents and sharp curves.

Heritage Reservation, a summer residence camp for the Boy Scouts of America is also accessible from this part of US 40, via Dinner Bell Five Forks Road.

The National Pike then continues southeast toward the Maryland border after crossing the Youghiogheny River and entering Somerset County.

Needed by farmers and emigrants alike, the National Road would provide a stable route for trade through the Allegheny Mountains.

After the Revolutionary War, and an increase in migration westward, the newly formed national government realized that communication with the west would be difficult with the Appalachian Mountains separating the east coast from the western frontier.

[5] In 1806, Thomas Jefferson authorized the construction of the Cumberland Road—the first federally funded highway in American history.

Made of cast-iron, these obelisk markers were placed every one mile and noted the distance to Cumberland and Wheeling and nearby towns.

The navigation of the Monongahela River after the construction of several locks and dams gave the National Road access to Pittsburgh via Brownsville.

Touring along the National Road was popular and many of the businesses returned to offer services to this new type of consumer.

The Post Office Appropriation Act of 1912 and the Rural Road Act of 1916 provided funds to rebuild the National Road, and World War I and the overburdened railroads made national highways a priority in the early twentieth century.