U.S. Route 101 in California
U.S. Route 101 is a major north–south United States Numbered Highway, stretching from Los Angeles, California, to Tumwater, Washington. The California portion of US 101 is one of the last remaining and longest U.S. Routes still active in the state, and the longest highway of any kind in California. US 101 was also one of the original national routes established in 1926. Significant portions of US 101 between the Los Angeles area and the San Francisco Bay Area follow El Camino Real, the commemorative route connecting the former Alta California's 21 missions.
Although the highway has been superseded in overall importance for transportation through the state by Interstate 5, US 101 continues to be the major coastal north–south route that links the Greater Los Angeles Area, the Central Coast, the San Francisco Bay Area, and the North Coast. Generally referred to as "101" by residents of Northern California, in Southern California it is often called "The 101". The highway has portions designated as the Santa Ana Freeway, the Hollywood Freeway, the Ventura Freeway, South Valley Freeway, and Bayshore Freeway, as well as El Camino Real in many non-freeway segments. The Redwood Highway, the northernmost segment of the highway, begins at the Golden Gate and passes through the world's tallest and only extensive preserves of virgin, old-growth coast redwood trees.
Route description
Running through California, US 101 is defined in section 401 of the California Streets and Highways Code simply as Route 101:Route 101 is from:
Route 5 near Seventh Street in Los Angeles to Route 1, Funston approach, and, subject to Section 72.1, the approach to the Golden Gate Bridge in the Presidio of San Francisco via Santa Barbara, San Luis Obispo, and Salinas.
A point in Marin County opposite San Francisco to the Oregon state line via Crescent City.
The definition purposely omits the segment crossing the Golden Gate Bridge, as it is maintained by the Golden Gate Bridge, Highway and Transportation District and is not part of the state highway system. The American Association of State Highway and Transportation Officials 's U.S. Route logs, along with most maps, have included the bridge as part of US 101, despite California's legal definition. The bridge along with the rest of US 101 is also part of the National Highway System, a network of highways that are considered essential to the country's economy, defense, and mobility by the Federal Highway Administration.
US 101 is part of the California Freeway and Expressway System, and portions of it are eligible to be included in the State Scenic Highway System. It is officially designated as a scenic highway by the California Department of Transportation from Goleta to Las Cruces in Santa Barbara County, and through Del Norte Coast Redwoods State Park in Del Norte County. This designation means that there are substantial sections of highway passing through a "memorable landscape" with no "visual intrusions", where the potential designation has gained popular favor with the community.
Southern California
US 101 begins in Los Angeles at the East Los Angeles Interchange, a major freeway junction that includes I-5, I-10, and SR 60. This six-lane portion of the route is the northerly continuation of the Santa Ana Freeway, inheriting that title from I-5. After, US 101 curves west and reaches the San Bernardino Split, a three-way junction with the San Bernardino Freeway that transitions into I-10 to the east. US 101 travels on a 1944 bridge over the Los Angeles River before passing the Los Angeles Union Station.Proceeding in a generally northwestern direction, US 101 runs through downtown Los Angeles via the Downtown Slot beneath the northern edge of Los Angeles Civic Center, and encounters SR 110 at the Four Level Interchange. Starting here, US 101 is named the Hollywood Freeway. The route then passes through the L.A. neighborhoods and into Hollywood, sharing a short segment with SR 2 through the urban area. US 101 runs up the Santa Monica Mountains through Cahuenga Pass before descending into the San Fernando Valley. It passes right next to the Universal Studios Hollywood before reaching the Hollywood Split where it abruptly shifts westward, superseding SR 134 on the Ventura Freeway, while the Hollywood Freeway continues northward as SR 170.
From the interchange, US 101 is an east–west highway. Such geographical orientation of the Ventura Freeway and the north–south designation which appears on the freeway signs can be confusing to visitors. The same freeway entrance can often be signed as "101 North" and "101 West"; this is most common in the San Fernando Valley where the local east-west signing does not match the Caltrans' proper statewide north-south designation. US 101 meets with I-405 in Sherman Oaks, and with Topanga Canyon Boulevard in the Woodland Hills neighborhood. By Calabasas, US 101 undergoes a change of scenery to a somewhat rural character, from a heavily urbanized scene observed since its southern terminus, as it enters Canejo Valley, where it crosses the border of Los Angeles County into Ventura County. In Thousand Oaks, US 101 has an overlap with SR 23 for about, until the three-way interchange with the Moorpark Freeway that SR 23 follows.
Continuing westward, US 101 climbs the Conejo Grade on a 7%-grade incline before descending into the Oxnard Plain, where it serves Camarillo and Oxnard. The coastside SR 1 runs concurrently on the freeway starting at Oxnard; there is no signage confirming the overlap despite maps depicting this. Upon crossing the Santa Clarita River, the two routes reach Ventura, where the freeway has an interchange with SR 126 and SR 33.
Central Coast
US 101 crosses the Ventura River that runs through the Emma Wood State Beach. It is at this point that the route comes within view of the Pacific Ocean for the first time on its journey. The route passes La Conchita before crossing into Santa Barbara County and encountering SR 150 that links Lake Casitas; at this point, the "Ventura Freeway" name ends, but US 101 continues as a freeway. In Santa Barbara, US 101 has a junction with SR 154. In Goleta, US 101 encounters SR 217 that connects to the University of Santa Barbara. Thereafter, US 101 narrows to four lanes, gradually tapering down from ten since Hollywood, and switches from freeway to expressway, albeit with several interchanges serving the beaches and parks along the Gaviota Coast. This rural stretch of highway often comes no more than from the shore. At Gaviota, US 101 sharply curves north, thus resuming its original north-south alignment, and heads inland across the Santa Ynez Mountains, where the northbound lanes pass through the Gaviota Tunnel.Throughout the rest of the Central Coast, US 101 oscillates between freeway and expressway status, but has unimpeded traffic as there are no traffic signals until San Francisco.
A few miles north of the Gaviota Tunnel, SR 1 splits from US 101 and heads northwest into Lompoc to resume its role as the primary coastal highway. US 101 heads into Buellton, where it encounters SR 246. North of town, US 101 meets with SR 154 a second time, and SR 135 at Los Alamos. By Orcutt, US 101 picks up a overlap with SR 166 until north of Santa Maria, where US 101 also reconnects with SR 135.
Image:101DescendingCuestaGrade.png|thumb|left|Southbound downhill view of Cuesta Grade toward San Luis Obispo.
In San Luis Obispo County, US 101 encounters SR 227 at Arroyo Grande. The highway collects SR 1 in another overlap as it passes through the oceanfront town of Pismo Beach. With SR 1 still in tow, US 101 heads back inland into San Luis Obispo, where SR 227 loops back into the highway and SR 1 splits off for Big Sur. North of San Luis Obispo, US 101 ascends the Cuesta Grade on a steep 7% grade within the Santa Lucia Range, cresting at an elevation of. At the bottom of the mountain, the route encounters SR 58 that links to Santa Margarita, and is an important byway to Bakersfield and Barstow. US 101 then enters Atascadero, where it meet SR 41 that interconnects the town with Morro Bay and Fresno. Upon reaching Templeton, US 101 is joined by SR 46 for about until Paso Robles, where it heads east serving as an alternate route to SR 41. After San Miguel, US 101 crosses into Monterey County while bisecting the Coast Guard post grounds of Camp Roberts.
US 101 bypasses the San Ardo Oil Field about south of the proverbial location. Between San Lucas and King City, The highway crosses the river three times and encounters SR 198, which provides a critical link east to Hanford. US 101 travels through the Salinas Valley, known by the motto "America's Salad Bowl" for its agricultural significance. Heading northwestward, it cuts through small valley towns before reaching Salinas, where it encounters SR 68 that provides an important connection with Monterey, and SR 183 close to the city's center. North of Salinas, US 101 has an interchange with SR 156 at Prunedale that follows it for the next approximately. Making a brief trek into San Benito County, US 101 arrives at SR 129, while at the same time, SR 156 splits off the highway on an interchange near San Juan Bautista. Within the same area, US 101 crosses the seismically-active San Andreas Fault.
San Francisco Bay Area
Entering the San Francisco Bay Area, US 101 crosses the Pajaro River into Santa Clara County and quickly arrives at an interchange with SR 25, which heads southeast into Hollister. As US 101 reaches Gilroy, it becomes a steady freeway for the South Bay. In town, SR 152 meets with US 101 and runs concurrently north for before branching off west into the business district. US 101 remains on the east sides of San Martin and Morgan Hill as it runs through the Santa Clara Valley.The surroundings become increasingly urbanized as US 101 reaches San Jose, the largest city in the Silicon Valley. The freeway arrives at the interchange of SR 85, the first Bay Area freeway encountered. The route stays east of Downtown San Jose, passing through largely residential areas and arrives at the Joe Colla Interchange, the meeting point for I-280 and I-680. Continuing its course, US 101 turns west-northwest through north San Jose and meets with I-880, which serves cities along the East Bay shoreline, and a partial interchange with SR 87. Upon entering Sunnyvale, the route encounters the two freeway junctions of SR 237 and SR 85, for the second time, by Moffett Field. Throughout its trek in the South Bay, US 101 passes by or near the campuses of major technology corporations, including IBM, Intel, Nvidia, and Google.
By Palo Alto, US 101 enters the San Francisco Peninsula. The freeway serves communities along the west edge of the San Francisco Bay, which is occasionally viewable from the roadway. At East Palo Alto, US 101 enters San Mateo County and meets with SR 84, which runs across the bay on the Dumbarton Bridge. US 101 passes through Redwood City, Belmont, and San Carlos, and in San Mateo the route encounters SR 92, another key bay crossing over the San Mateo Bridge. At San Bruno, US 101 passes the San Francisco International Airport, with direct ramp and flyover connections between the freeway and the terminals. It then arrives at I-380, which links with I-280 that has mostly avoided much of the urban areas. US 101 stays on the east side of South San Francisco. However, the scenery briefly yet abruptly changes to more natural as the freeway passes Brisbane on the east side of the San Bruno Mountain, running along a causeway separating the Brisbane Lagoon from the bay, before reaching Bayview Park, the location of the now-demolished Candlestick Park.
Image:Golden gate2.jpg|thumb|The Golden Gate Bridge, which carries US 101 and SR 1 between San Francisco and Marin County. US 101 enters the city and county of San Francisco and meets with I-280 again on the Alemany Maze. It reaches the western terminus of the San Francisco Skyway, which is signed as I-80 but not officially defined as such. US 101 turns west and follows the old Central Freeway viaduct near the city's Civic Center before suddenly transitioning northward on Van Ness Drive, the first time that US 101 is carried along a surface street, upon which bus lanes for MUNI run through the middle of the street. The alignment also passes behind the city hall. US 101 turns west on Lombard Street; this alignment serves as the boundary between the Marina District and Pacific Heights. After the Palace of Fine Arts, US 101 transitions onto the grade-separated Presidio Parkway through the namesake park. This divided roadway passes through two pairs of the Presidio Tunnels and curves northward just as SR 1 joins the route near Crissy Field. The shared highways cross the Golden Gate Bridge.
From San Francisco north, US 101 is a vital freeway thoroughfare for commuters in the North Bay. After crossing the Golden Gate Bridge, US 101 enters Marin County as the Redwood Highway. This leg of the freeway serves the urbanized eastern side of the county fronting San Pablo Bay. It climbs the Waldo Grade and passes through the Robin Williams Tunnel; afterward, it passes above the hillside town of Sausalito and descends to Richardson Bay, where SR 1 splits from the freeway and heads to the Pacific coast. Through Mill Valley, US 101 has a junction with the west end of SR 131 that provides a connection with Tiburon and a ferry service to Angel Island. US 101 passes through the twin towns of Corte Madera and Larkspur, running by the Larkspur Ferry Terminal. In San Rafael, US 101 encounters the partial junction of I-580 before running just east of the downtown area and the Marin County Civic Center. Farther north in Novato, the route encounters SR 37 that links to Vallejo, and runs alongside the Olompali State Historic Park on the northern outskirts. This outlying area that the freeway traverses is sparsely populated, as the voter-approved Novato–Petaluma Community Separator protects it against most development.
US 101 crosses into Sonoma County, where vineyard patches frequently dot the open spaces surrounding the freeway, indicating entry into Wine Country. In Petaluma, US 101 picks up a concurrency with SR 116 that extends into Cotati, where SR 116 splits off west to Sebastopol. US 101 continues northward through neighboring Rohnert Park, home of the Sonoma State University and the Graton Resort. At downtown Santa Rosa, it has a junction with SR 12 and passes over the Railroad Square on the Robert L. Bishop Memorial Bridge, an elevated span. Upon reaching Windsor, US 101 becomes more lightly traveled as the landscape gradually evolves into a more bucolic setting. The freeway crosses the Russian River in Healdsburg and then parallels the river up the Alexander Valley, where it avoids the winegrowing valley floor by grazing the west hills overlooking the valley. SR 128 joins US 101 at Geyserville, then leaves the freeway at Cloverdale. US 101 then ascends a steep hill just before leaving the Bay Area.