U.S. Route 101
The nearly highway's northern terminus is in Tumwater, Washington: the route remains along the Olympic Peninsula's coastal perimeter west, north, and east; the northernmost point on the highway is in Port Angeles. The southern terminus of US 101 is in Los Angeles at the East Los Angeles Interchange, the world's busiest freeway interchange.
U.S. Route 151
US 151 was one of the original U.S. Highways from 1926. At the time, it only ran from Fond du Lac, Wisconsin to Madison. Originally, the highway ended at Western Avenue and Main Street in Madison. In 1934, the highway was extended southwest to Cedar Rapids, Iowa, incorporating the full length of former U.S. Highway 118 (Dodgeville to Dickeyville) and part of former U.S. Highway 161 (Dubuque to Cedar Rapids; US 161 from Cedar Rapids south to Keokuk became US 218). At the time, the southern end of the route was at Williams Blvd SW and 16th Ave SW, what was then US 30 and US 218. In the 1940s, the highway was extended northeast to Manitowoc.