U.S. Route 20
U.S. Highway 20 (US 20) is an east–west United States highway that stretches from the Pacific Northwest all the way to New England. The "0" in its route number indicates that US 20 is a coast-to-coast route. Spanning , it is the longest road in the United States, and particularly from Newport, Oregon to Boston, Massachusetts, the route is roughly parallel to that of the newer Interstate 90 (I-90), which is in turn the longest Interstate Highway in the U.S. There is a discontinuity in the official designation of US 20 through Yellowstone National Park, with unnumbered roads used to traverse the park.
U.S. Route 40 in Maryland
U.S. Route 40 (US 40) in the U.S. state of Maryland runs from western Maryland to Cecil County in the state's northeastern corner. With a total length of over , it is the longest numbered highway in Maryland. Almost half of the road overlaps or parallels with Interstate 68 or Interstate 70, while the old alignment is generally known as U.S. Route 40 Alternate, U.S. Route 40 Scenic, or Maryland Route 144. West of Baltimore, in the Piedmont and 
Appalachian Mountains / Blue Ridge region of the Western Maryland panhandle of the small state, the portions where it does not overlap an Interstate highway are mostly two-lane roads. The portion northeast of Baltimore going to Wilmington, in northern Delaware and Philadelphia in southeastern Pennsylvania before crossing the Susquehanna River at the north end of the Chesapeake Bay, is a four-lane divided highway, known as the Pulaski Highway (named for American Revolutionary War (1775-1783) foreign military volunteer of Polish cavalry officer Casimir Pulaski, 1745-1779).