U.S. Highway 101, or U.S. Route 101 (U.S. 101), is a north-south highway that is aligned along the Pacific West Coast of the United States. Its counterpart is U.S. Highway 1 (U.S. 1) aligned along the Atlantic East Coast of the United States. Note that U.S. Highway 1 should NOT be confused with California State Highway 1 (CA/SR-1), also known as the "Pacific Coast Highway". U.S. Route 101 is often referred to as the Pacific Highway, especially in Oregon, and parts of Washington and California. Colloquially, the highway is also referred to as The 101 by residents of Southern California or simply 101 by residents of Northern California.
U.S. Route 101 once was the major north-south link along the Pacific coast. It has been replaced in importance by the highways of the Interstate Highway System, specifically Interstate 5 (I-5), which are more modern in their physical design. Note that this highway is still in use and as an alternative to the Interstates throughout its entire length. One of the notable exceptions is where the alignment of I-5 is on the alignment of U.S. Route 101 (that is, the pavement is the same but the route number changed to I-5 and U.S. Route 101 was decommissioned) beginning about one mile east of downtown Los Angeles and continuing south to San Diego.
In Southern California, the highway is a heavily traveled commuter route serving the west side of the Greater Los Angeles area. Communities or cities along the alignment include the various west-side districts of Los Angeles including Hollywood and the south side of the San Fernando Valley, and the cities of West Hollywood, Burbank, Thousand Oaks, and Agoura Hills.
The south terminus of U.S. Route 101 is in Los Angeles, about one mile east of downtown Los Angeles at the East Los Angeles Interchange complex. Between this interchange and the junction with the California State Highway 134 (CA/SR-134), Ventura Freeway, it is known as the Hollywood Freeway. At the junction with CA/SR-134, the alignment of U.S. 101 'shifts' to the alignment of CA/SR-134 (i.e. heading northbound, the road's alignment turns left, or westbound) and thereafter is referred to as the Ventura Freeway. Confusingly, the "Hollywood Freeway" name continues northward from this interchange on another highway (California State Highway 170 (CA/SR-170)). From the 101/134/170 interchange to Ventura, U.S. 101 is an east-west highway until it reaches Gaviota State Park where it shifts to a north-south alignment.
Beginning at Ventura, the highway closely follows the Pacific coastline (generally no more than one to two miles from the shore) until Gaviota State Park about 20-25 miles west of Goleta, California. North of Ventura the highway is an intermittent freeway (i.e. at several locations there are traffic signals, at grade intersections, etc.). Communities and cities along the alignment north of Ventura include Santa Barbara, San Luis Obispo, Salinas, Gilroy, San Jose, Palo Alto, and San Francisco.
See the page for the California State Highway 1 (CA/SR-1) "Pacific Coast Highway", that runs along the Pacific coastline in California, parallel, and to the west of, U.S. Route 101, for more information.
From San Jose to San Francisco, Highway 101 is known as the Bayshore Freeway. Through San Francisco Highway 101 follows city streets, then joins California State Route 1 to cross the Golden Gate Bridge to Marin County. From there to the Oregon border, Highway 101 is in some places a freeway and in others a two-lane road. The most scenic portion of Highway 101 within California is in Humboldt County, where it travels through Humboldt Redwoods State Park and a portion of the highway is known as the Avenue of the Giants for the huge, centuries-old redwood trees that can be found there.
Highway 101 enters Oregon four miles south of Brookings, and is seldom out of sight of the Pacific Ocean until it reaches Astoria. The stretch between Florence and Yachats is considered one of the more attractive segments of this highway, although there are an abundance of Oregon state parks along the Pacific coast. Because Highway 101 forms the main street of almost all of the coastal towns in Oregon (with the exception of Cannon Beach and others), it is frequently congested and slow. The highway crosses the mouth of the Columbia River at the bridge at Astoria into Washington, and follows the Columbia downstream to Ilwaco.
From Ilwaco, Highway 101 follows the Pacific coastline as far as Raymond, from which it proceeds directly north to Aberdeen, offering access from this city into the Olympic National Park. While the AAA has designated this segment north and east to Port Angeles as a scenic byway, some clear-cut logging in the early 1990s has diminished the scenic value of the highway where it crosses the Quinault Indian Reservation. East of Port Angeles Highway 101 turns southward, leading to its northern terminus in Olympia, the state capital.
Parts of Historic Route 101 can still be found in San Diego County between Oceanside and La Jolla under different names, including Interstate 5, Pacific Highway, Camino Del Mar, and Torrey Pines Road. All have been decommissioned, but the roadways still exist and are occasionally signed as Historic 101.
As of 2004, the highway's "northern" terminus is in Olympia, Washington at an intersection with Interstate 5. However, the section from Olympia to Aberdeen is a large loop around the Olympic Peninsula, and is signed "US 101 North". The direct route between the towns is US 12. Its southern terminus is in Los Angeles, California at the East Los Angeles Interchange, the world's busiest freeway interchange. (http://www.scvresources.com/highways/east_los_angeles_interchange.htm)
The highway passes through the following states (north to south):
Related U.S. routes