U.S. 101 is an important north–south US federal Highway that runs through the U.S. state of California, and to Los Angeles on the West Coast of the United States and Mexico known as El Camino Real (The Royal Road) where its route along the southern and central California coast approximates the old trail which linked the Spanish missions, pueblos, and presidios. It merges at some points with California Highway 1. According to the AASHTO's numbering scheme for U.S. Highways, three-digit route numbers are generally subsidiaries of two-digit routes. However, the principal north–south routes were assigned numbers ending in 1. Rather than lose four available north–south numbers (93, 95, 97, and 99) or assign the primary west coast highway a "lesser" number, the AASHTO made an exception to its two-digit rule. Thus, U.S. 101 is treated as a primary, two-digit route with a "first digit" of 10, rather than a spur of U.S. 1 or I-5. Thus U.S. 101 is the westernmost major U.S. federal highway. Though U.S. 101 remains a major coastal north–south link along the Pacific coast north of San Francisco, it has been replaced in overall importance for transport through the West Coast states by Interstate 5, which is more modern in its physical design , and is thouroghly limited access highway unlike U.S. 101. Thus, I-5 has more direct placement due to significantly easier geography over much of the route. U.S. 101 is a major freeway or highway between Los Angeles and San Francisco, and is an alternate to California astate Highway 1 or Interstate 5 for most of its length. In 1964, California truncated its southern terminus in Los Angeles, as Interstate 5 replaced it. The old road is known as county road S-21 or Historic Route 101 in northern San Diego County. The nearly Template:Convert-long highway's "northern" terminus is near Trindad, California U.S. 101 may be called the "Pacific Highway" in parts of California. It is also called "The 101" (pronounced "the one oh one") by residents of Southern California or simply "101" by residents of Northern California,. From north of San Francisco and continuing almost to Oregon it is also referred to as the "Redwood Highway". Urban portions of the route in Southern California are named the Santa Ana Freeway, Hollywood Freeway, and Ventura Freeway at various points between East Los Angeles and Carpinteria, California. In 2008, the portion of the freeway that runs from the Conejo Grade to the Old Town district of Camarillo was dedicated as the Adolfo Camarillo Memorial Highway to honor the city's namesake and extends through the boundaries of the original Camarillo family rancho. Urban portions of the route in the Bay Area are called the James Lick Freeway, Bayshore Freeway, and Central Freeway. A portion of the route north of Salinas, California is named Sig Sanchez Highway. Street routings in San Francisco are more commonly referred to by their street names rather than the route number. Portions of the route between Southern California and the Bay Area are named El Camino Real or El Camino Real Freeway, but such names are rarely used colloquially in lieu of the route number. Route 101 is considered part of Pacific Coastal Highway.
- Main article: U.S. Route 101 in California
In Southern California, the highway is a heavily traveled commuter route serving the Northwest portion of the greater Los Angeles area; this includes Ventura County communities in the West Conejo Valley and in the Oxnard Plain, along with Los Angeles County communities in the East Conejo Valley and San Fernando Valley. The route is the Santa Ana Freeway from East Los Angeles to Downtown Los Angeles. It becomes the Hollywood Freeway north of Downtown Los Angeles through the Cahuenga Pass, before turning west and becoming the Ventura Freeway. Communities along the alignment include Hollywood and the southern edge of the San Fernando Valley, and the cities of Hidden Hills, Calabasas, Agoura Hills, Westlake Village, Thousand Oaks (includes Newbury Park), Camarillo, Oxnard, Ventura, Santa Barbara, and San Luis Obispo. I-101 also integrates with the southern part of the historic El Camino Real.In Northern California it is the primary coastal route providing motorists access in and out of the San Francisco Bay Area. It is also the primary commuter route carrying residents of Marin and Sonoma into San Francisco. For commuters of San Mateo County, San Jose, and other cities that make up Silicon Valley it shares this duty with Interstate 280. The route proceeds northward (via Van Ness Ave., Lombard St., and Richardson St.), leaving the City of San Francisco by crossing the Golden Gate Bridge. It then departs the immediate coast and continues through wine country and Redwood forests until it re-emerges coast-side at Eureka. The route provides access through the extraordinary terrain of the North Coast
California does not sign the long east–west section of U.S. 101 between Point Conception and its junction with California State Route 134 and 170 in North Hollywood as "West" and "East." Instead, Caltrans observes the overall direction of the highway and marks these portions as "North" and "South". Local references to this portion of the freeway, including traffic reports, refer to the directions on this section as east for southbound lanes and west for northbound lanes. In the late 1990s, Caltrans began placing guide signs on local streets in the San Fernando Valley adjacent to 101 which identified eastbound and westbound entrances to the freeway. Other than replacing older guide signs which previously referenced the official northbound and southbound designations of the freeway, Caltrans made no other changes to mainline or street signing, and as such, pull-through signs, History
Parts of Historic Route 101 can still be found in San Diego County between Oceanside and the border with Mexico under a variety of different names. Through Oceanside it is called Coast Highway. In Carlsbad it becomes Carlsbad Blvd, but to the south in Encinitas it is Coast Interstate 101. Solana Beach keeps it consistent with Highway 101, but Del Mar changes it to Camino Del Mar. All of those together make up San Diego County Route S21. From there it continues along Torrey Pines Road to Interstate 5 in La Jolla. The old 101 routing continues on I-5 in San Diego until Pacific Highway, the old U.S. 101 freeway a little west of current I-5. It then continued on Harbor Drive and Broadway through Downtown San Diego and Chula Vista, then onto National City Blvd in National City. The southern parts of I-5 were U.S. 101 for a period before I-5 was completed also. All have been decommissioned, but the roadways still exist and are occasionally signed as Historic 101.
Most of Historic 101 between Gilroy and San Francisco is still active, either signed as Business 101 or as State Route 82. The 101 bypass, however, is mostly discontinuous and is paralleled by the actual freeway, in some cases serving as an access road to the freeway. Large parts of the old U.S. Business 101 and State Route 82 surface roads between San Francisco and San Diego are designated El Camino Real (The Royal Road), a designation originally given any thoroughfare under the direct authority of the King of Spain and his viceroys. These portions constitute the first major road in California. Before the Golden Gate Bridge was completed, U.S. 101 was divided in the San Francisco Bay Area. 101-W (west) followed the same general right-of-way of today's 101 from San Jose to San Francisco. 101-E (east) generally followed the right-of-way taken by today's I-880 from San Jose to Oakland, then across the Carquinez Bridge to follow what is now California State Route 37, joining 101-W. Since there was no Golden Gate Bridge yet, 101-W became a ferry ride across the Golden Gate Strait. As today, 101-W proceeded up Van Ness, but without any left turn at Lombard, ending at the Hyde Street Pier. From there, motorists would drive onto a ferry boat which would cross the Golden Gate to Sausalito, where they would drive off the ferry directly onto the main street of Sausalito, which was signed for U.S 101 once again. The 101-E designation was removed by the 1940s and became state Route 17 (later Interstates 880 and 580) between San Jose and Santa Cruz. As the Bayshore Freeway was built along the east side of the San Francisco peninsula in the early 1950s, old U.S. 101 along the El Camino Real was posted as U.S. 101 Alternate or 101-a, and the freeway was marked U.S. 101-Bypass or 101-B. In 1964, when California renumbered numerous state highways, El Camino was renumbered California 82 and the Bayshore Freeway lost the Bypass designation.
U.S. 101 has become internationally renowned over the years in film, popular culture and song. It is often quoted alongside other legendary roadtrip routes, such as Route 66, as a recognized symbol of American culture and lifestyle. The highway itself is depicted in several episodes of The O.C., set in Southern California, and is both the feature and focus of its theme song "California" by Phantom Planet. It is also referenced in Albert Hammond Jr.'s track "101", "Black Planet" by The Sisters of Mercy, "Ventura Highway" by America, "Black Denim Trousers and Motorcycle Boots" by The Cheers, "Surf Route 101" by Jan and Dean, Canadian hip-hop artist Buck 65's track "Highway 101", a Herb Alpert instrumental titled "Route 101" and in Social Distortion's track "Highway 101 ". US 101 is also one of the courses in the racing game Cruis'n USA.