What is the longest highway in the U.S.?
U.S. Route 20
Western segment
Oregon
US101 at West Olive Street in Newport
I-5 in Albany
US97 in Bend
US395 in Riley. The highways travel concurrently to northeast of Burns.
US26 in Vale. The highways travel concurrently to Mountain Home, Idaho.
Idaho
US95 north of Parma. The highways travel concurrently to southeast of Parma.
I-84 / US30 north of Caldwell. The highways travel concurrently to Caldwell.
I-184 in Boise. The highways travel concurrently through the city.
I-84 / US30 in Boise. The highways travel concurrently to Mountain Home.
US26 / US93 in Carey. US20/US26 travel concurrently to northwest of Atomic City. US20/US93 travel concurrently to Arco.
I-15 in Idaho Falls. The highways travel concurrently through the city.
Montana
US191 / US287 at Firehole Avenue in West Yellowstone. The highways travel concurrently to West Thumb.
Wyoming
US89 north-northwest of West Thumb. The highways travel concurrently to West Thumb.