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.
Connecticut Route 101
In 1922, Connecticut numbered its state highways. The turnpike from Phoenixville to west of Pomfret Landing was designated as part of Route 101. The original Route 101 began in South Chaplin, where it split off from New England Route 3. It ran northward via modern Route 198 to Phoenixville then turned eastward along the Connecticut and Rhode Island Turnpike (modern Route 44) to west of Pomfret Landing. Route 101 then continued along modern Route 44 northward to Pomfret Center and eastward through Putnam to the Rhode Island line. Route 101 followed modern Route 44 through Rhode Island all the way to Plymouth, Massachusetts. At the same time, the eastern half of the Connecticut and Rhode Island Turnpike was designated as Highway 137 west of Route 12 and Highway 139 east of Route 12.