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 101 in California
After merging with westbound traffic from the San Bernardino Freeway (I-10), US 101 then proceeds northwest via the Downtown Slot under the northern edge of Los Angeles' Civic Center to State Route 110 (SR 110) at the Four Level Interchange. From here, US 101 becomes the Hollywood Freeway. It then heads to Hollywood and up through the Cahuenga Pass before reaching the San Fernando Valley.