<P> 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 3,365 miles ( 5,415 km ) , 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 . </P>
<P> 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 3,365 miles ( 5,415 km ) , 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 . </P>
what is the longest route in the united states
what is the longest route in the united states
U.S. Highway 20 ( US 20 )
U.S. Highway 20 ( US 20 )