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 9 in New York
US 9 spawns more letter-suffixed state highways than any other route in New York, including the longest, New York State Route 9N (NY 9N). Outside of the cities it passes through, it is a mostly a two-lane road, save for two expressway segments in the mid-Hudson region. For much of its southern half it follows the Hudson River closely; in the north it tracks I-87 (the Adirondack Northway).