The Arroyo Seco Parkway, also known as the Pasadena Freeway, is one of the oldest freeways built in the United States. It connects Los Angeles with Pasadena alongside the Arroyo Seco seasonal river. It is notable not only for being an early freeway, mostly opened in 1940, but for representing the transitional phase between early parkways and later freeways. It conformed to modern standards when it was built, but is now regarded as a narrow, outdated roadway. A 1953 extension brought the south end to the Four Level Interchange in downtown Los Angeles and a connection with the rest of the freeway system.
Route 110, consisting of State Route 110 (SR 110) and Interstate 110 (I-110), is a state and auxiliary Interstate Highway in the Los Angeles metropolitan area of the US state of California. The entire route connects San Pedro and the Port of Los Angeles with Downtown Los Angeles and Pasadena. The southern segment from San Pedro to I-10 in downtown Los Angeles is signed as I-110, while the northern segment to Pasadena is signed as SR 110. The entire length of I-110, as well as SR 110 south of the Four Level Interchange with US Route 101 (US 101), is the Harbor Freeway, and SR 110 north from US 101 to Pasadena is the historic Arroyo Seco Parkway, the first freeway in the western United States.
Route 710, consisting of the non-contiguous segments of State Route 710 (SR 710) and Interstate 710 (I-710), is a major north–south state highway and auxiliary Interstate Highway in the Los Angeles metropolitan area of the U.S. state of California. Also called the Los Angeles River Freeway prior to November 18, 1954, the highway was initially planned to connect Long Beach and Pasadena, but a gap in the route exists from Alhambra to Pasadena through South Pasadena due to community opposition to its construction.
Interstate 405 is a major north–south auxiliary Interstate Highway in Southern California. The entire route is known as the northern segment of the San Diego Freeway. I-405 is a bypass auxiliary route of I-5, running along the southern and western parts of the Greater Los Angeles urban area from Irvine in the south to Sylmar in the north.
The Hollywood Freeway is one of the principal freeways of Los Angeles, California and one of the busiest in the United States. It is the principal route through the Cahuenga Pass, the primary shortcut between the Los Angeles Basin and the San Fernando Valley. It is considered one of the most important freeways in the history of Los Angeles and instrumental in the development of the San Fernando Valley. It is the second oldest freeway in Los Angeles. From its southern end at the Four Level Interchange to its intersection with the Ventura Freeway in the southeastern San Fernando Valley, it is signed as part of U.S. Route 101. It is then signed as State Route 170 north to its terminus at the Golden State Freeway.
The Ventura Freeway is a freeway in southern California, United States, that runs from the Santa Barbara/Ventura county line to Pasadena in Los Angeles County. It is the principal east–west route through Ventura County and in the southern San Fernando Valley in Los Angeles County. From the Santa Barbara County line to its intersection with the Hollywood Freeway in the southeastern San Fernando Valley in Los Angeles, it is signed as U.S. Route 101 (US 101), which was built in the late 1950s and opened on April 5, 1960. The segments from the Santa Barbara County line to Sea Cliff, and from Solimar Beach to Oxnard, are also concurrent with State Route 1 (SR 1), although no signs mention SR 1 there. East of the Hollywood Freeway intersection, the Ventura Freeway is signed as State Route 134 (SR 134), which was built by 1971.
The East Los Angeles Interchange is an interchange complex located in Boyle Heights, Los Angeles, approximately 2.5 miles east of Downtown Los Angeles. With its southern portion handling over 550,000 vehicles per day, it is the busiest freeway interchange in the world. The northern portion, called the San Bernardino Split, is often considered a separate interchange. Four numbered routes converge at the interchange: Interstate 5 (I-5), I-10, U.S. Route 101 (US 101), and State Route 60 (SR 60), but the freeway segments shift alignments and directions.
State Route 2 (SR 2) is a state highway in the U.S. state of California. It connects the Los Angeles Basin with the San Gabriel Mountains and the Victor Valley in the Mojave Desert. The highway's southwestern end is at the intersection of Centinela Avenue at the Santa Monica-Los Angeles border and its northeastern end is at SR 138 east of Wrightwood. The SR 2 is divided into four segments, and it briefly runs concurrently with U.S. Route 101 (US 101) and Interstate 210 (I-210). The southwestern section of SR 2 runs along a segment of the east–west Santa Monica Boulevard, an old routing of US 66, to US 101 in East Hollywood; the second section runs along segments of both the north–south Alvarado Street and Glendale Boulevard in Echo Park; the third section to I-210 in Glendale is known as the north–south Glendale Freeway; and the northeastern portion from I-210 in La Cañada Flintridge to SR 138 is designated as the Angeles Crest Highway.
The Four Level Interchange is the first stack interchange in the world. Completed in 1949 and fully opened in 1953 at the northern edge of Downtown Los Angeles, California, United States, it connects U.S. Route 101 to State Route 110. In 2006, the interchange was officially renamed in the memory of Los Angeles traffic and weather reporter Bill Keene.
Colorado Boulevard is a major east–west street in Southern California. It runs from Griffith Park in Los Angeles east through Glendale, the Eagle Rock section of Los Angeles, Pasadena, and Arcadia, ending in Monrovia. The full route was once various state highways but is now locally maintained in favor of the parallel Ventura Freeway and Foothill Freeway (I-210).
State Route 118 is a state highway in the U.S. state of California that runs west to east through Ventura and Los Angeles counties. It travels from State Route 126 at the eastern edge of Ventura immediately northwest of Saticoy, then through Saticoy, in Ventura County east to Interstate 210 near Lake View Terrace in Los Angeles. SR 118 crosses the Santa Susana Pass and the northern rim of the San Fernando Valley along its route.
State Route 126 is a state highway in the U.S. state of California that serves Ventura and Los Angeles counties. The route runs from U.S. Route 101 in Ventura to Interstate 5 at the Castaic Junction-Santa Clarita border through the Santa Clara River Valley. The highway is an important connector highway in Ventura County, and serves as an alternate route into the Santa Clarita Valley, and the San Fernando Valley area of Los Angeles and the High Desert of Antelope Valley.
State Route 23 is a state highway in the U.S. state of California that connects the Pacific coast and the Santa Monica Mountains to the Conejo and Santa Clara River valleys. It runs from Pacific Coast Highway in Malibu in Los Angeles County to Ventura Street in Fillmore in Ventura County.
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 Foothill Freeway is a freeway in the Los Angeles metropolitan area, California, United States, running from the Sylmar district of Los Angeles east to Redlands. The western segment is signed as Interstate 210 (I-210) from its western end at I-5 to SR 57 in Glendora, while the eastern segment is signed as State Route 210 (SR 210) to its eastern terminus at I-10. Under the California Streets and Highways Code, the entire Foothill Freeway is legally referred to as Route 210.
State Route 41 is a state highway in the U.S. State of California, connecting the Central Coast with the San Joaquin Valley and the Sierra Nevada. Its southern terminus is at the Cabrillo Highway in Morro Bay, and its northern terminus is at SR 140 in Yosemite National Park. It has been constructed as an expressway from near SR 198 in Lemoore north to the south part of Fresno, where the Yosemite Freeway begins, passing along the east side of downtown and extending north into Madera County.
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 10 (I-10) is a transcontinental Interstate Highway in the United States, stretching from Santa Monica, California, to Jacksonville, Florida. The segment of I-10 in California runs east from Santa Monica through Los Angeles, San Bernardino, and Palm Springs before crossing into the state of Arizona. In the Greater Los Angeles area, it is known as the Santa Monica and San Bernardino freeways, linked by a short concurrency on I-5 at the East Los Angeles Interchange. I-10 also has parts designated as the Rosa Parks and Sonny Bono Memorial freeways. Some parts were also formerly designated as the Christopher Columbus Transcontinental Highway. However, the California State Legislature removed this designation following the passage of a bill on August 31, 2022. I-10 is also known colloquially as "the 10" to Southern California residents (See also California English § Freeways).
Interstate 5 (I-5) is a major north–south route of the Interstate Highway System in the United States, stretching from the Mexican border at the San Ysidro crossing to the Canadian border near Blaine, Washington. The segment of I-5 in California runs 796.77 miles (1,282.28 km) across the length of the state from San Ysidro to the Oregon state line south of the Medford-Ashland metropolitan area. It is the longest interstate in California, and accounts for more than half of I-5's total length.
Greater Los Angeles has a complex multimodal transportation infrastructure, which serves as a regional, national and international hub for passenger and freight traffic. The transportation system of Greater Los Angeles includes the United States' largest port complex, seven commuter rail lines, Amtrak service, a subway system within the city of Los Angeles, and numerous highways. Los Angeles is integrated into the Interstate Highway System by Interstate 5, Interstate 10, and Interstate 15, along with numerous auxiliary highways and state routes. Bus service is also included locally within the area by numerous local government agencies. Subways and light commuter rail lines are present within Los Angeles proper, allowing mass transportation within the city. Commuter railroads are run by Metrolink. Amtrak has numerous railroad lines that connect Los Angeles to the rest of the country.
US 101 
SR 170 
US 101 (Ventura Freeway/Hollywood Freeway) – Ventura , Los Angeles 
SR 134 east (Ventura Freeway) – Pasadena 
SR 170 north (Hollywood Freeway) – Sacramento 
