The City of Los Angeles is served by a large network of freeways, streets, and local and regional public transportation systems. California's first freeway (though not the nation's first) was the 110 Freeway, also known as the Pasadena Freeway or the Arroyo Seco Parkway. It opened in January 1, 1940 and links downtown Los Angeles to downtown Pasadena. From Chavez Ravine north to Pasadena can be quite dangerous because there is no shoulder, the lanes are narrow, the turns are sharp (and not always properly banked), and the ramps are quite short and offer little room for acceleration to freeway speed. Commercial vehicles over 6,000 pounds are prohibited from using this freeway. More recent freeways are straighter, wider and allow for higher speeds.

Angelenos are noted for referring to freeways with the definite article ("The 101"), in contrast to most other areas of the United States, who omit the article. Referring to freeways by name, for example "The San Diego Freeway", is essentially a holdover from the time when the freeways were built, and is diminishing. Nevertheless, freeways continue to be officially named, and the 118 was recently christened The Ronald Reagan Freeway.

The primary regional public transportation agency is the Los Angeles County Metropolitan Transportation Authority (LACMTA), commonly referred to as Metro or MTA. The agency, which operates bus, light rail and subway services, averages 1.6 million transit trips per weekday, making it the third largest transit agency in the United States. Other municipal transportation agencies in Los Angeles County (Long Beach Transit, Montebello Bus Lines, Norwalk Transit, Redondo Beach, Santa Monica's Big Blue Bus, Santa Clarita Transit, Torrance Transit and Foothill Transit) have an additional 405,000 average weekday boardings.

In February 2008, LACMTA introduced a new universal fare system called 'TAP' which stands for Transit Access Pass. The TAP smart card allows bus and rail passengers to tap their cards on the farebox for faster boarding. TAP readers have already been installed on buses and rail stations next to ticket vending machines. Because Metro Rail is a barrier free system, fare inspectors will be checking to make sure TAP users have validated their card use a wireless handheld unit. This automated fare system will eventually be implemented on 11 other Los Angeles County transit operators and intends to replace the EZ Pass which allows travel between these transit agencies for one monthly price. Commuters from surrounding cities and communities will be able to travel across the county switching from one transit operator's system to another using one smart card to pay for fares.

The extensive bus system operated by LACMTA includes the Metro Local, Metro Rapid and Metro Express services. The buses have an estimated 1.3 million boardings on the weekdays. Including other municipal bus operators, Los Angeles County averages 1.7 million bus boardings per weekday, accounting for approximately 5.9% of the 29 million daily trips originating in Los Angeles County.

LACMTA has bus rapid transit system called the Orange Line, that runs from Warner Center/Woodland Hills to the North Hollywood Red Line station, began operations on October 29, 2005. For 13 of its 14 mile stretch (21 km of its 22.5 km stretch), the 60-foot articulated buses, built by North American Bus Industries and dubbed Metro Liners, operate on bus-only lanes that follow an old railroad right-of-way. Portions of the route parallel Chandler and Victory Boulevards, and Oxnard Street.

Foothill Transit also operates a bus rapid transit system called the Silver Streak, which runs from Montclair to Downtown Los Angeles along the El Monte Busway on Interstate 10.

Between its light rail and heavy rail systems, Los Angeles Metro Rail has 73 miles (117 km) miles of rail, averaging 308,653 trips per weekday, and accounting for approximately 1.1% of the 29 million daily trips originating in Los Angeles County. The network includes three above-ground light rail lines (Gold Line, Blue Line and Green Line) and one underground subway with two branches (Red Line and Purple Line). Ranked by daily ridership, the Los Angeles subway ranked as the 9th-busiest rapid transit system in the United States. Ranked by passengers per route mile, however, the system ranks 6th, transporting 8,846 passengers per route mile, more than San Francisco's Bay Area Rapid Transit or the Chicago 'L'.

The Los Angeles Metro Rail system connects disperse areas of the county including Long Beach, Pasadena, Norwalk, El Segundo, North Hollywood and Downtown Los Angeles. As of June 2008, two additional light rail lines were under construction: the Expo Line's first phase from Downtown Los Angeles to Culver City and an extension of the Gold Line from Union Station to East Los Angeles. There are additional rail expansion projects currently under study. The timing of their construction will depend on the availability of funding.

Also serving Los Angeles and several surrounding counties is Metrolink, a regional commuter rail service. Metrolink averages 42,600 trips per weekday.