what is the longest road in the usa
U.S. Route 20 (US 20) is an eastâwest United States highway. The 0 in its route number indicates that US 20 is a coast-to-coast route. Spanning 3,365 miles (5,415 km), it is the longest road in the United States, and the route roughly parallels that of Interstate 90 (I-90). There is a discontinuity in the official designation of US 20 through Yellowstone National Park, with unnumbered roads used to traverse the park. It and US 30 break the general U.S. Route numbering rules in Oregon, since US 30 actually starts north of US 20 and runs parallel to the north throughout the state.