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.
Interstate 5 in Oregon
Interstate 5 is the second-longest freeway in Oregon, at , and is the only Interstate to traverse the state from north to south. The highway connects several of the state's largest metropolitan areas, which lie in the Rogue and Willamette valleys, and passes through counties with approximately 81 percent of Oregon's population. As a component of the Interstate Highway System, I-5 is also designated as an important highway under the National Highway System. It is officially designated under Oregon's named route system as the Pacific Highway No. 1, a name shared with Oregon Route 99 (OR 99) and its split routes north of Junction City. OR 99 runs concurrent to I-5 through most of southern Oregon, splitting from the freeway to serve city centers and use other alternate routes, while OR 99W and OR 99E serve corridors on opposite sides of the Willamette River. The state legislature also designated I-5 as the Purple Heart Trail and Korean War Veterans Memorial Highway in 2015.