U.S. Route 101, or U.S. Highway 101 (US 101), is a major north–south highway that traverses the states of California, Oregon, and Washington on the West Coast of the United States. It is part of the United States Numbered Highway System and runs for over 1,500 miles (2,400 km) along the Pacific Ocean. The highway is also known by various names, including El Camino Real in parts of California, the Oregon Coast Highway, and the Olympic Highway in Washington. Despite its three-digit number, normally used for spur routes, US 101 is classified as a primary route.
Interstate 880 (I-880) is a north–south auxiliary Interstate Highway in the San Francisco Bay Area of Northern California. It runs from I-280 and State Route 17 (SR 17) in San Jose to I-80 and I-580 in Oakland, running parallel to the eastern shore of San Francisco Bay. For most of its route, I-880 is officially known as the Nimitz Freeway, after World War II fleet admiral Chester W. Nimitz, who retired to the Bay Area. The northernmost five miles (8.0 km) is also commonly referred to as the Cypress Freeway, after the former alignment of the freeway and its subsequent replacement.
Interstate 280 (I-280) is a 57.22-mile-long (92.09 km) major north–south auxiliary Interstate Highway in the San Francisco Bay Area of Northern California. It runs from I-680 and US Route 101 (US 101) in San Jose to King and 5th streets in San Francisco, running just to the west of the larger cities of San Francisco Peninsula for most of its route.
Interstate 380 (I-380) is a short 3.3-mile (5.3 km) east–west auxiliary Interstate Highway in the San Francisco Bay Area of Northern California, connecting I-280 in San Bruno to US Route 101 (US 101) near San Francisco International Airport. The highway primarily consists of only three intersections: I-280, State Route 82, and US 101. Like the nearby I-280, I-380 never connects to I-80, its parent Interstate Highway. However, there is no rule that says that spur routes need to do so.
The Bayshore Freeway is a part of U.S. Route 101 in the San Francisco Bay Area of the U.S. state of California. It runs along the west shore of the San Francisco Bay, connecting San Jose with San Francisco. Within the city of San Francisco, the freeway is also known as James Lick Freeway, named after the California philanthropist. The road was originally built as a surface road, the Bayshore Highway, and later upgraded to freeway standards. Before 1964, it was mostly marked as U.S. Route 101 Bypass, with US 101 using the present State Route 82.
Route 238, consisting of State Route 238 (SR 238) and Interstate 238 (I-238), is a mostly north–south state and auxiliary Interstate highway in the San Francisco Bay Area of California. The southern segment is signed as SR 238 and is a divided multilane surface highway that runs parallel to the Hayward hills between I-680 in Fremont and I-580 in Castro Valley. The northern segment is signed as I-238 and is a six-lane freeway that runs more east–west between I-580 and I-880 in San Leandro.
State Route 92 is a state highway in the U.S. state of California, serving as a major east-west corridor in the San Francisco Bay Area. From its west end at State Route 1 in Half Moon Bay near the coast, it heads east across the San Francisco Peninsula and the San Mateo–Hayward Bridge to downtown Hayward in the East Bay at its junction with State Route 238 and State Route 185. It has interchanges with three freeways: Interstate 280, U.S. Route 101 in or near San Mateo, and Interstate 880 in Hayward. It also connects indirectly to Interstates 238 and 580 by way of Hayward's Foothill Boulevard, which carries Route 238 and flows directly into Route 92.
State Route 87, known as the Guadalupe Freeway or referred to by the locals as Highway 87, is a north–south state highway in San Jose, California, United States. Before being upgraded to a freeway, it was Guadalupe Parkway.
State Route 237 is a state highway in the U.S. state of California that runs from El Camino Real in Mountain View to Interstate 680 in Milpitas. Known as the Southbay Freeway for most of its length, SR 237 runs south of the San Francisco Bay, connecting the East Bay to the Peninsula.
State Route 123 is a 7.39-mile (11.89 km) state highway in the U.S. state of California in the San Francisco Bay Area. Named San Pablo Avenue for almost its entire length except for its northernmost 0.10 miles (0.16 km), SR 123 is a major north–south state highway along the flats of the urban East Bay. Route 123 runs between Interstate 580 in Oakland in the south and Interstate 80 at Cutting Boulevard in Richmond in the north. San Pablo Avenue itself, a portion of Historic US 40, continues well past the SR 123 designation south to Downtown Oakland and north to Crockett.
State Route 72 is a state highway in the U.S. state of California. The route runs along Whittier Boulevard in the Los Angeles area from SR 39 in La Habra to Interstate 605 in Whittier. SR 72 forms part of El Camino Real.
State Route 84 is a state highway in the U.S. state of California that consists of two unconnected segments, one in the San Francisco Bay Area and the other primarily in the Sacramento–San Joaquin River Delta area.
State Route 61 is a state highway in the U.S. state of California, running along the eastern edge of Oakland International Airport and through Alameda. Two additional "hidden" state highways, State Route 112 and State Route 260, are also signed as part of SR 61, despite having legal descriptions separate from Route 61.
State Route 17 is a state highway in the U.S. state of California that runs from State Route 1 in Santa Cruz to I-280 and I-880 in San Jose. SR 17, a freeway and expressway, carries substantial commuter and vacation traffic through the Santa Cruz Mountains at Patchen Pass between Santa Cruz and the San Francisco Bay Area.
State Route 185 is a state highway in the San Francisco Bay Area of the U.S. state of California. It runs along sections of Mission Boulevard in Hayward, East 14th Street in San Leandro and International Boulevard in Oakland. At its south end, SR 185 connects with State Routes 92 and 238 in Hayward. At the north end of SR 185 at International Boulevard and 42nd Avenue, the short State Route 77 heads southwest to Interstate 880.
U.S. Route 101 (US 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.
Interstate 80 (I-80) is a transcontinental Interstate Highway in the United States, stretching from San Francisco, California, to Teaneck, New Jersey. The segment of I-80 in California runs east from San Francisco across the San Francisco–Oakland Bay Bridge to Oakland, where it turns north and crosses the Carquinez Bridge before turning back northeast through the Sacramento Valley. I-80 then traverses the Sierra Nevada, cresting at Donner Summit, before crossing into the state of Nevada within the Truckee River Canyon. The speed limit is at most 65 mph (105 km/h) along the entire route instead of the state's maximum of 70 mph (110 km/h) as most of the route is in either urban areas or mountainous terrain. I-80 has portions designated as the Eastshore Freeway and Alan S. Hart Freeway.
A total of fifteen special routes of U.S. Route 101 exist.
Junipero Serra Boulevard is a major boulevard in and south of San Francisco named after Franciscan friar Junipero Serra. Within the city, it forms part of the route of State Route 1, the shortest connection between Interstate 280 and the Golden Gate Bridge. The remainder, in San Mateo County, was bypassed or replaced by I-280, the Junipero Serra Freeway. The boulevard was one of several new roads built along the San Francisco Peninsula before the age of freeways, and became a state highway known as Route 237 in 1956, receiving the State Route 117 designation in the 1964 renumbering, only to be deleted from the state highway system the next year. Two other regional highways—Bayshore Highway and Skyline Boulevard—were also upgraded into or bypassed by freeways.
Monterey Road is a major Silicon Valley thoroughfare that runs from Gilroy north to San Jose, California, in Santa Clara County. It follows the historic route of El Camino Real and is an old alignment of U.S. Route 101.
I-880 in San Jose (State Maintenance)
I-280 in San Francisco 
