Southern California freeways
This article needs additional citations for verification. (April 2010) ( Learn how and when to remove this template message)
The Southern California freeways are a vast network of interconnected freeways in the megaregion of Southern California, serving a population of 23 million people. The Master Plan of Metropolitan Los Angeles Freeways was adopted by the Regional Planning Commission in 1947 and construction began in the early 1950s.  The plan hit opposition and funding limitations in the 1970s, and by 2004, only some 61% of the original planned network had been completed.
The region is well known for its freeways, and they are considered a cultural touchstone.
This section needs additional citations for verification. (February 2008) ( Learn how and when to remove this template message)
Southern California's romance with the automobile owes in large part to resentment of the Southern Pacific Railroad's tight control over the region's commerce in the late 19th and early 20th centuries. During his successful campaign for governor in 1910, anti-Southern Pacific candidate Hiram Johnson traveled the state by car, which was no small feat at that time. In the minds of Southlanders, this associated the automobile with clean, progressive government, in stark contrast to the railroads' control over the corrupt governments of the Midwest and Northeast. While the Southern Pacific-owned Pacific Electric Railway's famous Red Car streetcar lines were the axis of urbanization in Los Angeles during its period of spectacular growth in the 1910s and 1920s, they were unprofitable and increasingly unattractive compared to automobiles. As cars became cheaper and began to fill the region's roads in the 1920s, Pacific Electric lost ridership. Traffic congestion soon threatened to choke off the region's development altogether. At the same time, a number of influential urban planners were advocating the construction of a network of what one widely read book dubbed "Magic Motorways", as the backbone of suburban development. These " greenbelt" advocates called for decentralized, automobile-oriented development as a means of remedying both urban overcrowding and declining rates of home ownership.
Traffic congestion was of such great concern by the late 1930s in the Los Angeles metropolitan area that the influential Automobile Club of Southern California engineered an elaborate plan to create an elevated freeway-type "Motorway System," a key aspect of which was the dismantling of the streetcar lines, to be replaced with buses that could run on both local streets and on the new express roads.  In the late 1930s, when the freeway system was originally planned locally by Los Angeles city planners, they had intended for light rail tracks to have been installed in the center margin of each freeway (which would presumably have carried Pacific Electric Railway red cars), but this plan was never fully implemented. 
During World War II, transportation bottlenecks on Southern California roads and railways convinced many that if Southern California was to accommodate a large population, it needed a completely new transportation system. The city of Los Angeles favored an upgraded rail transit system focused on its central city. However, the success of the Arroyo Seco Parkway, built between Los Angeles and Pasadena in 1940, convinced many that a freeway system could solve the region's transportation problems. Leaders of surrounding cities, such as Whittier, South Gate, Long Beach, and Pasadena, accordingly called for a web of freeways to connect the whole region, rather than funneling their residents out of their own downtowns and into that of Los Angeles. Pro-freeway sentiments prevailed, and by 1947, a new comprehensive freeway plan for Los Angeles (based largely on the original locally planned 1930s system, but without the light rail tracks in the median strips of the freeways) had been drawn up by the California Department of Public Works (now Caltrans). San Diego soon followed suit, and by the early 1950s, construction had begun on much of the region's freeway system.
This article needs additional citations for verification. (September 2020) ( Learn how and when to remove this template message)
Caltrans or local transportation agencies have identified the following priority freeway projects:
- An extension for State Route 57 from the Orange Crush interchange to Interstate 405.
- A toll road that will go through a tunnel in the Santa Ana Mountains from Irvine to Corona.
- Upgrading State Route 210 to Interstate standards and renumbering the route Interstate 210. 
- A new freeway across the Santa Ana Mountains to relieve congestion on State Route 91, the Riverside Freeway, to provide a new route between the Inland Empire and southern Orange County. 
- A new freeway, the Mid County Parkway, from Interstate 215 in Perris to State Route 79 in San Jacinto. 
- An extension for Interstate 710, the Long Beach Freeway, to its originally planned terminus at Interstate 210, Foothill Freeway, in Pasadena, via a tunnel underneath the city of South Pasadena  or some other means.
- An extension to the State Route 241 toll road to meet Interstate 5 in or near San Clemente. 
- Upgrading State Route 71, the Chino Valley Freeway, to a full controlled-access freeway north of State Route 60, the Pomona Freeway, to Interstate 10, the San Bernardino Freeway, in Pomona. 
- Upgrading State Route 55, the Costa Mesa Freeway, from south of its current freeway terminus at 19th Street in Costa Mesa to State Route 1, Pacific Coast Highway, in Newport Beach, potentially via a tunnel. 
- Construction of the High Desert Corridor, a freeway and expressway between State Route 14, the Antelope Valley Freeway, in Palmdale and Interstate 15, the Mojave Freeway, near Victorville. It would also carry a high-speed rail line to Las Vegas, Nevada.   Caltrans put the freeway on hold in 2019. 
- State Route 48 is a completely unconstructed 25.5-mile (41.03 km) freeway to connect at the current SR 14/138 junction and West Avenue E, go east running parallel with East Avenue E and East Avenue G, and terminate in Hi Vista at East Avenue G/200th Street East, at the planned SR 122 freeway.
- State Route 122 is a completely unconstructed 61.3-mile (98.7 km) freeway, defined to run from SR 14 south of Palmdale, and proceed northeast through Hi Vista, and terminate at the current U.S. 395/SR 58 at Kramer Junction.
- State Route 249 is a 13.5-mile (21.7 km) unconstructed route that would connect SR 2 north of La Cañada Flintridge with SR 14 south of Palmdale. Angeles Forest Highway (CR N3) follows the general alignment, but Caltrans has no plans to take it over. However, there are plans to explore the building of this route between Palmdale and Los Angeles by tunneling through the mountains.
- A toll road that would run from State Route 126 to State Route 118 in Simi Valley through the Santa Susana Mountains. This would ease congestion in Simi Valley. The only north-south highways that connect SR 126 with SR 118 are I-5 and SR 23. Motorists on SR 126 can use this route to reach Simi Valley without having to use Interstate 5 via Newhall Pass to SR 118 or SR 23 to Moorpark and vice versa. A good traversable route would be Tapo Canyon Road, Windmill Canyon Road, and Pico Canyon Road, but Caltrans has no plans to take it over.
Southern California residents idiomatically refer to freeways with the definite article, as "the [freeway number]", e.g. "the 5" or "the 10". This use of the article differs from other American dialects, including that of Northern California, but is the same as in the UK (e.g. "Take the M1 to the M25") and other European countries (e.g. "La A1"). In addition, sections of the southern California freeway system are often referred to by names rather than by the official numbers. For example, the names Santa Monica and San Bernardino are used for segments of the Interstate 10 even though overhead freeway signs installed at interchanges since the 1990s don't display these names, using instead the highway number, direction, and control city. A freeway 'name' may refer to portions of two or more differently numbered routes; for example, the Ventura Freeway consists of portions of U.S. Route 101 and State Route 134, and the San Diego Freeway consists of portions of Interstate 5 and the full length of Interstate 405.
When Southern California freeways were built in the 1940s and early 1950s, local common usage was primarily the freeway name preceded by the definite article.  It took several decades for Southern California locals to start to also commonly refer to the freeways with the numerical designations, but the usage of the definite article persisted. For example, it evolved to "the 605 Freeway" and then shortened to "the 605". 
- Four Level ( Bill Keene Memorial): US 101 / SR 110
- Dosan Ahn Chang Ho Memorial: I-10 / I-110 / SR 110
- East Los Angeles: I-5 / I-10 / SR 60 / US 101
- Hollywood Split (Bruce T. Hinman Memorial): US 101 / SR 134 / SR 170
- Judge Harry Pregerson: I-105 / I-110
- El Toro Y: Southern junction of I-5 / I-405
- Kellogg: I-10 / SR 57 / SR 71
- Orange Crush: I-5 / SR 22 / SR 57
- Newhall Pass (Clarence Wayne Dean Memorial): I-5 / SR 14
- Glendora Curve: SR 57 / I-210 / SR 210
- Jack Schrade (Mission Valley Viaduct): I-8 / I-805
- Marilyn Jorgenson Reece Memorial Interchange: I-10 / I-405
- Downtown Slot: where Highway 101 passes through a trench in Downtown Los Angeles.
- South Bay Curve: where Interstate 405 bends from north–south to east–west in Torrance
- Sepulveda Pass: Interstate 405 just south of U.S. Route 101 near the J. Paul Getty Museum.
- Cahuenga Pass: the Hollywood Freeway just south of the interchange with the Ventura Freeway
- Figueroa Street Tunnels: the northbound lanes of the Pasadena Freeway between the Four Level Interchange and the interchange with the Golden State Freeway
- Glendora Curve: the transition of the northbound 57 Orange Freeway to the westbound 210 Foothill Freeway; or the eastbound 210 transition to the southbound 57. Formerly part of Interstate 210 before the completion of the newer section of the Foothill Freeway in 2003.
- First freeway in California ( Arroyo Seco Parkway linking Pasadena and Los Angeles)
- First stack interchange ( Four Level Interchange in downtown Los Angeles)
- First grade-separated HOV lanes[ citation needed]
- First fully automated tollway system ( 91 Express Lanes in northern Orange County)
The Southern California area has fewer lane-miles per capita than most large metropolitan areas in the United States, ranking 31st of the top 39. As of 1999, Greater Los Angeles had 0.419 lane-miles per 1,000 people, only slightly more than Greater New York City and fewer than Greater Boston, the Washington Metropolitan Area and the San Francisco Bay Area. (American metros average .613 lane-miles per thousand.) San Diego ranked 17th in the same study, with 0.659 lane-miles per thousand, and the Inland Empire ranked 21st, with 0.626. 
The following of Limited-access roads are not maintained by the state:
- Colorado Street, former routing of State Route 134, from Interstate 5 to San Fernando Road just west of Glendale
- Colorado Freeway, former routing of State Route 134, from Colorado Blvd in Eagle Rock to the Ventura Freeway
- Harbor Scenic Drive from Interstate 710 at Ocean Boulevard to RMS Queen Mary
- Jamboree Road in Irvine, a non-tolled extension of State Route 261 from Walnut Avenue near Interstate 5 to Barranca Parkway
- Oak Grove Drive in Pasadena, former routing of the Foothill Freeway
- Shoreline Drive in Long Beach, the downtown exit from southbound Interstate 710 to Queens Way
- La Cienega Boulevard in the Baldwin Hills, originally intended to be part of the discontinued Laurel Canyon Freeway
- Los Patrones Parkway in Las Flores, a non-tolled extension of State Route 241 from Oso Parkway to Cow Camp Road
- Interstate 5 south terminus at San Ysidro in San Diego, northbound to the Central Valley and Sacramento
- Interstate 8 west terminus in Ocean Beach in San Diego, eastbound to the Arizona State Line towards Yuma
- Interstate 10 west terminus in Santa Monica, eastbound to the Arizona State Line towards Phoenix
Interstate 15 south terminus in Barrio Logan in
San Diego, northbound to the
Nevada State Line towards
- Wabash Freeway (signed as State Route 15) from Barrio Logan in San Diego to Interstate 805
- Escondido Freeway from Interstate 805 to the San Diego- Riverside County Line
- Temecula Valley Freeway from the San Diego-Riverside County Line to Lake Elsinore
- Corona Freeway from Lake Elsinore to Corona
- Ontario Freeway from Corona to the Devore neighborhood of San Bernardino
- Mojave Freeway, also Barstow Freeway, from Devore to the Nevada State Line
- Interstate 40 west terminus in Barstow, eastbound to the Arizona State Line towards Kingman
- U.S. Route 101 south terminus at the East L.A. Interchange, westbound to Santa Barbara then northbound through the Central Coast region to Silicon Valley and San Francisco
- State Route 14, south terminus at Interstate 5 in Los Angeles, northbound to U.S. Route 395 and Bishop
- Interstate 5
- Interstate 8
- Interstate 15 and State Route 15
- State Route 52
- State Route 54
- State Route 56
- State Route 67
- State Route 75
- State Route 78
- State Route 94
- State Route 125
- State Route 163
- Interstate 805
- State Route 905
- Kearny Villa Road near Naval Air Station Miramar, former routing of U.S. Route 395
- Pacific Highway near San Diego International Airport ( Lindbergh Field), former routing of U.S. Route 101
- Friars Road in Mission Valley near Qualcomm Stadium (formerly Jack Murphy Stadium)
(Includes San Bernardino and Riverside Counties)
- Interstate 10
- Interstate 15
- Interstate 40
- State Route 60
- State Route 71
- State Route 91
- Interstate 210 and State Route 210
- Interstate 215
(includes Los Angeles, Orange, Riverside, San Bernardino, Ventura Counties)
- State Route 1
- State Route 2
- Interstate 5
- Interstate 10
- State Route 14
- Interstate 15
- State Route 22
- State Route 23
- State Route 33
- State Route 47
- State Route 55
- State Route 57
- State Route 58
- State Route 60
- State Route 71
- State Route 73
- State Route 90
- State Route 91
- U.S. Route 101
- State Route 103
- Interstate 105
- Interstate 110
- State Route 110
- State Route 118
- State Route 133
- State Route 134
- State Route 138
- State Route 170
- Interstate 210 and State Route 210
- Interstate 215
- State Route 241
- State Route 261
- Interstate 405
- Interstate 605
- Interstate 710
- http://latimesblogs.latimes.com/thedailymirror/2008/06/june-15-1938.html "Motorways Plan Revealed: System of Roads Designed to Cure Traffic Ills," Los Angeles Times, June 15, 1938
- Hall, Peter Cities in Civilization: Culture, Technology, and Urban Order, London, Weidenfeld & Nicolson, 1998; New York, Pantheon Books, 1998 See section on Los Angeles
- Fagin, Daniel (May 7, 2016). "Routes 209-216". California Highways.[ self-published source]
- "Schedule", octa.net, archived from the original on October 10, 2012
- "Schedule", pe.com
- "Schedule", dot.ca.gov
- "Schedule". octa.net.
- "Schedule", mission71project.com
- "Schedule", octa.net
- "Schedule", dot.ca.gov
- Sahagun, Louis (February 10, 2018). "L.A. County set to build its first new freeway in 25 years, despite many misgivings". Los Angeles Times. Retrieved July 31, 2018.
- "Editorial: It was a terrible idea to build a new freeway in Los Angeles County. Now it's on hold for good". Los Angeles Times. October 6, 2019. Retrieved October 17, 2019.
- Geyer, Grant (Summer 2001). "'The' Freeway in Southern California". American Speech. 76 (2): 221–224. doi: 10.1215/00031283-76-2-221.
- http://www.publicpurpose.com/hwy-tti99ratio.htm publicpurpose.com
- Carney, Steve. "From Superhighways To Sigalerts: Freeways Have Become Part Of Southland's Identity." Los Angeles Daily News, September 21, 1999, p. N4. ^
- Hise, Greg (1999). Magnetic Los Angeles: Planning the Twentieth-Century Metropolis. Johns Hopkins University Press. ISBN 0-8018-6255-8.
- Taylor, Brian (2004). "The Geography of Urban Transportation Finance," pp 294–331 in Hanson and Giuliano eds., The Geography of Urban Transportation, 3rd Edition. The Guilford Press. ISBN 1-59385-055-7.
- Schrank and T. Lomax, The Urban Mobility Report 2007. Texas Transportation Institute.
- The History of Southern California Freeway Development
- Southern California Area Highways Page
- California Department of Transportation Live Streaming Traffic Cams
- California Highway Patrol Los Angeles Traffic Incident Information Page
- Sigalert Los Angeles Traffic Report
- Los Angeles Freeway Descriptions
- California Department of Transportation Named Freeways ( PDF file)
-  Southern California Trucking Accidents
- California Institute for Telecommunications Wireless Traffic Reports for Southern Cal
- The Urban Mobility Report 2007, Texas Transportation Institute
- Should I buy a home near the freeway? (from SCPCS)