World Library  
Flag as Inappropriate
Email this Article

Interstate 405 (California)

Interstate 405 marker

Interstate 405
San Diego Freeway
Route information
Defined by Streets and Highways Code § 615
Maintained by Caltrans
Length: 72.415 mi[1] (116.541 km)
Existed: 1964 – present
Major junctions
South end: I‑5 in Irvine
  SR 55 in Costa Mesa
SR 22 / I‑605 in Seal Beach
I‑710 in Long Beach
I‑110 in Carson
I‑105 near LAX Airport
I‑10 in West Los Angeles
US 101 in Sherman Oaks
North end: I‑5 near San Fernando
Highway system
US 395 SR 480

Interstate 405 (usually pronounced four-oh-five), also known as I-405 or "the 405", is a major north–south Interstate Highway in Southern California. It is a bypass of Interstate 5, running along the western and southern parts of the Greater Los Angeles Area from Irvine in the south to near San Fernando in the north. The entire route is known as the northern segment of the San Diego Freeway.

I-405 is a heavily traveled thoroughfare by both commuters and by freight haulers along its entire length and is the busiest and most congested freeway in the United States.[2][3] The freeway's annual average daily traffic between exits 21 and 22 in Seal Beach reached 374,000 in 2008, making it the highest count in the nation.[4] It has played a crucial role in the development of dozens of cities and suburbs along its route through the Greater Los Angeles area.

This route is part of the California Freeway and Expressway System.[5]


  • Route description 1
    • Points of interest 1.1
  • History 2
    • "Carmageddon" 2.1
  • In progress 3
    • Sepulveda Pass Improvements Project 3.1
  • Future 4
    • Manchester and Century Boulevard interchanges 4.1
    • Orange County 4.2
  • Incidents 5
    • UCLA protest 1966 5.1
    • The O.J. Simpson chase 1994 5.2
    • Murder of Ennis Cosby 1997 5.3
  • In popular culture 6
  • Exit list 7
  • References 8
  • External links 9

Route description

I-405 in the Sepulveda Pass

Interstate 405 begins at the El Toro Y interchange with Interstate 5 in southeastern Irvine. It then runs northwest through Orange County to Long Beach in Los Angeles County. The freeway then roughly follows the outline of the Pacific coast, varying between five and ten miles (16 km) inland before crossing over the Sepulveda Pass in the Santa Monica Mountains. I-405 next travels northerly through the San Fernando Valley, before its termination with I-5 in the Mission Hills district of Los Angeles. Large portions of the route closely parallel Sepulveda Boulevard.

The San Diego Freeway, near the interchange with the Ventura Freeway (U.S. Route 101)

The freeway's congestion problems are legendary, leading to jokes that the road was numbered 405 because traffic moves at "four or five" miles per hour, or because drivers need "four or five" hours to get anywhere. Indeed, average speeds as low as 5 mph are routinely recorded during morning and afternoon commutes, and its interchanges with the Ventura Freeway (U.S. Route 101) and with the Santa Monica Freeway (Interstate 10) each consistently rank among the five most congested freeway interchanges in the United States. As a result of these congestion problems, it may take longer to pass through the entire Los Angeles area using this bypass route instead of merely taking the primary route I-5 through Downtown.

Of the major reasons for the excessively heavy traffic on the freeway, the 405 is the only major North-South freeway in the densely populated areas between West LA and Downtown, crossing the Santa Monica Mountains and connecting San Fernando Valley and the Los Angeles basin. Another parallel freeway is actually needed to connect SF Valley and central LA basin (proposed as Laurel Canyon Freeway or La Cienaga Freeway); not only to reduce the strain on 405 but also ease heavily trafficked and time consuming East-West drives on arterial streets through numerous traffic lights, however has not been built due to politics -- upper class movie star resident opposition.[6] Despite 4 years of construction disruptions, billions of dollars of public money, LA Times commentary claims traffic with the lane expansions is actually just as bad or worse.[7]

Commuters are known to despise the freeway. Steve Harvey of the Los Angeles Times once featured a personalized license plate with the text HATE405 in his column.

Points of interest

The Bristol exit near South Coast Plaza and Segerstrom Center for the Arts, with Saddleback in the background

There are a number of points of interest that I-405 passes by or connects to. For transportation, these include (in the order passed from south to north) John Wayne Airport in Orange County, Long Beach Municipal Airport and Los Angeles International Airport. With connections, it is also very close to the Port of Long Beach, the Port of Los Angeles and Burbank Airport.

Some of the educational institutions it passes include the California state universities at Dominguez Hills, Long Beach, and Northridge; the University of California at Irvine and UCLA, Loyola Marymount University, and Pepperdine University's West LA and Irvine campuses.

I-405 also passes cultural facilities such as the Getty Center, the Skirball Cultural Center and the Segerstrom Center for the Arts. In addition, several shopping malls such as Sherman Oaks Galleria, Westfield Culver City, The Promenade at Howard Hughes Center, Westminster Mall, South Coast Plaza and the Irvine Spectrum Center are located along I-405.

The route also passes by or through many recreation and commercial destinations. These include more than ten California state beaches, several other beaches owned by counties and municipalities, many of the beach cities favored by tourists, as well as Century City and Marina del Rey.

The view from the Getty Center, south of the Sepulveda Pass, looking east, south, and west. The San Diego Freeway can be seen at the center


1955 map of the planned Interstates in the Los Angeles area. Present-day I-405 roughly corresponds to the 1955 proposed route through the western regions of the area.
Marilyn Reece & Carol Schumaker, at the Reece-designed I-10/I-405 interchange, 1964

I-405 was approved as a chargeable interstate (in other words, an interstate financed with federal funds) in 1955. Construction began in 1957 with the first section, mostly north of LAX Airport being completed in 1961 (signed as SR 7) followed by sections west of Interstate 605 within the following few years. The highway was renumbered to Interstate 405 during the 1964 renumbering. The final section covering most of Orange County opened in 1969. Construction required the already existing Mulholland Highway to be re-routed 1.1 miles to the south along a new 579-foot-long bridge, the Mulholland Drive Bridge, to span Interstate 405.[8]

The freeway from present-day I-10 to I-5 near San Fernando was once known as the "Sepulveda Freeway" as it was named for Sepulveda Boulevard.[9]


A section of I-405 was closed over the weekend of Friday, July 15, 2011 as part of the Sepulveda Pass Improvements Project.[10] Before the closing, local radio DJs and television newscasts referred to it as "Carmageddon" and "Carpocalypse", parodying the notion of Armageddon and the Apocalypse, since it was anticipated that the closure would severely impact traffic.[11][12]

In reality, traffic was lighter than normal across a wide area. California Department of Transportation reported that fewer vehicles used the roads than usual, and those who did travel by road arrived more quickly than on a normal weekend.[13] The Metrolink commuter train system recorded its highest-ever weekend ridership since it began operating in 1991. Ridership was 50% higher than the same weekend in 2010, and 10% higher than the previous weekend ridership record, which occurred during the U2 360° Tour in June 2011.[14] In response to jetBlue Airlines' offer of special flights between Bob Hope Airport in Burbank and Long Beach Airport, a distance of only 29 mi (47 km), for $4,[15][16] a group of cyclists did the same journey in one and a half hours, compared to two and a half hours by plane (including a drive to the airport from West Hollywood 90 minutes in advance of the flight and travel time to the end destination).[17] There was also some debate about whether the Los Angeles area could benefit from car-free weekends on a regular basis.[13]

The Los Angeles County Metropolitan Transportation Authority had full closure of a 10-mile stretch of I-405 on the weekend of September 29–30, 2012, while construction crews worked to demolish a portion of the Mulholland Bridge.[18]

In progress

Sepulveda Pass Improvements Project

The $1 billion Sepulveda Pass Improvements Project will add a high-occupancy vehicle lane and associated changes to freeway entrances, exits, and underpasses along a 10-mile stretch through the Sepulveda Pass between I-10 and U.S. 101/Ventura Boulevard.[19] The project is to be completed as a design-build in contrast to the traditional design-bid-build used typically in infrastructure improvement. This section of I-405 was closed for a weekend in mid-July 2011 to demolish the Mulholland Drive Bridge, and a 10-mile section was closed for the last weekend of September 2012 (See 'Carmageddon 2011' and 'Carmageddon 2012' above).[10] Construction is expected to be completed in the summer of 2014.[20]

Jamzilla was the name for the 405 closure on President's Day Weekend 2014. There were lane closures and complete closures on the 405 Freeway started Feb. 14 at 10pm till Feb. 18 at 6 a.m to pave and re-stripe the northbound lanes.[21]

On May 23, 2014, the 10-mile high-occupancy vehicle lane was opened to traffic.[22]


Manchester and Century Boulevard interchanges

Proposed changes between the Manchester and Century Boulevard interchanges in Inglewood to provide a new southbound on-ramp and a new northbound off-ramp for Arbor Vitae Street, to reconstruct and widened the Arbor Vitae Street over-bridge and replace the Century Boulevard overcrossing structure.[23] This work would reduce congestion on the approach to Los Angeles International Airport. The California Department of Transportation has not issued a start date for this work.

Orange County

The Orange County Transportation Authority is currently studying a proposal to add a HOT lane between Highway 73 in Costa Mesa and I-605 in Seal Beach.[24]


UCLA protest 1966

Following the 1966 UCLA-USC rivalry game, USC was voted into the Rose Bowl despite the UCLA team's having defeated the Trojans—with both teams having only one loss during the season. UCLA students protested by blocking the freeway's northbound lanes at Wilshire Boulevard.

The O.J. Simpson chase 1994

While dangerous high-speed chases along the San Diego Freeway are not uncommon, perhaps the most famous chase in its history was also one of the slowest. On the afternoon of June 17, 1994, former football star O.J. Simpson, a suspect in the murder of his ex-wife Nicole Brown Simpson and waiter Ronald Goldman, took to the freeway in a white Ford Bronco (driven by former USC teammate Al Cowlings) with police in pursuit. A bizarre, widely televised low-speed chase ensued and ended hours later when Simpson returned to his Brentwood estate via the Sunset Boulevard exit and surrendered to law enforcement.[25]

Murder of Ennis Cosby 1997

Ennis Cosby, the only son of Bill Cosby, was murdered along I-405 in Los Angeles on January 16, 1997, while fixing a flat tire.[26]

In popular culture

I-405 was the location for the short film 405.

The Death Cab For Cutie song "405" on their second studio album, We Have the Facts and We're Voting Yes, is often incorrectly associated with California's I-405. The song is actually referring to I-405 in Seattle, Washington. The band is from Bellingham, and is referencing the songwriter's drive south to Seattle to visit a girlfriend at the time of writing.[27]

TV writer Chuck Lorre used his end-of-show vanity card #429 (November 2013) to berate workers on the 405 for their apparent lack of progress after five years.[28]

Exit list

Except where prefixed with a letter, postmiles were measured on the road as it was in 1964, based on the alignment that existed at the time, and do not necessarily reflect current mileage. R reflects a realignment in the route since then, M indicates a second realignment, L refers an overlap due to a correction or change, and T indicates postmiles classified as temporary (for a full list of prefixes, see the list of postmile definitions).[1] Segments that remain unconstructed or have been relinquished to local control may be omitted. The numbers reset at county lines; the start and end postmiles in each county are given in the county column.

County Location Postmile
Destinations Notes
ORA 0.23–24.18
Irvine 0.23 I‑5 south (San Diego Freeway) – San Diego Southbound exit and northbound entrance; former US 101 south; southern terminus; I-5 north exit 94A
  1A Lake Forest Drive Southbound exit and northbound entrance
  1B Bake Parkway Southbound exit and northbound entrance
0.95 1C Irvine Center Drive Signed as exit 1 northbound
1.80 2 SR 133 (Laguna Freeway) – Laguna Beach No northbound exit to SR 133 north; SR 133 north exit 8, south exits 8A-B
2.88 3 Shady Canyon Drive, Sand Canyon Avenue
3.95 4 Jeffrey Road, University Drive
5.62 5 Culver Drive
6.92 7 Jamboree Road
7.80 8 MacArthur Boulevard – John Wayne Airport
Costa Mesa 8.74 9A SR 55 (Costa Mesa Freeway) SR 55 north exit 6, south exits 6A-B
  9B Anton Boulevard, Avenue of the Arts Northbound exit and entrance
9.51 9B Bristol Street
10.28 10 SR 73 south (Corona del Mar Freeway) to SR 55 south (Costa Mesa Freeway) – San Diego via toll road Southbound exit and northbound entrance
  11 South Coast Drive Northbound exit only
10.75 11A Fairview Road Signed as exit 11 northbound
11.45 11B Harbor Boulevard – Costa Mesa Signed as exit 11 northbound
Fountain Valley 12.47 12 Euclid Street, Newhope Street, Ellis Avenue
13.78 14 Brookhurst Street – Fountain Valley
14.82 15A Warner Avenue east Southbound exit and northbound entrance
Huntington Beach 15.21 15B Magnolia Street, Warner Avenue west Signed as exit 15 northbound
16.54 16 SR 39 (Beach Boulevard) – Westminster, Huntington Beach
Westminster 17.75 18 Bolsa Avenue, Goldenwest Street Goldenwest Street is signed as Golden West Street
19.16 19 Westminster Avenue, Springdale Street
  20 Bolsa Chica Road Southbound exit only
20.75 21 SR 22 east (Garden Grove Freeway) / Valley View Street – Garden Grove South end of SR 22 overlap
Seal Beach 22.64 22 Seal Beach Boulevard, Los Alamitos Boulevard Former SR 35
23.28 23 SR 22 west (7th Street) – Long Beach North end of SR 22 overlap; I-605 exit 1A
24.04 24A I‑605 north (San Gabriel River Freeway) Signed as exit 24 northbound; I-605 south exits 1B-1C; SR 22 east exit 2
Los Angeles
LA 0.27–48.64
Long Beach 0.45 24B Studebaker Road Southbound exit and northbound entrance
1.11 25 Palo Verde Avenue
1.64 26A Woodruff Avenue No southbound exit
2.18 26B Bellflower Boulevard Signed as exit 26 southbound
3.32 27 SR 19 (Lakewood Boulevard) – Long Beach Airport
4.88 29 Spring Street, Cherry Avenue – Signal Hill Signed as exits 29A (south) and 29B (north)
Signal Hill 5.39 29C Orange Avenue
Long Beach 6.08 30A Atlantic Avenue
6.34 30B Long Beach Boulevard Former SR 15
6.70 32A Pacific Avenue Southbound exit and northbound entrance
7.60 32 I‑710 (Long Beach Freeway) – Long Beach, Pasadena Signed as exits 32A (north) and 32B (south) northbound, and 32B (south) and 32C (north) southbound; I-710 exit 4
8.06 32C Hughes Way, Santa Fe Avenue Signed as exit 32D southbound
Carson 8.78 33A Alameda Street (SR 47 south)
9.56 33B Wilmington Avenue
10.54 34 Carson Street
11.22 35 Avalon Boulevard – Carson Northbound exit to Avalon Boulevard south is via exit 34
12.60 36 Main Street Northbound exit and southbound entrance
12.97 37A I‑110 (Harbor Freeway) – San Pedro, Los Angeles Signed as exit 37 northbound; former US 6; I-110 exit 9
Los Angeles 13.28 37B Vermont Avenue Southbound exit and northbound entrance
13.83 38A Normandie Avenue – Gardena
14.40 38B Western Avenue
Torrance 15.45 39 Crenshaw Boulevard – Torrance
16.57 40A Artesia Boulevard - Redondo Beach Northbound exit to Artesia Boulevard east is via exit 39, southbound exit to Artesia Boulevard west is via exit 40B; former SR 91
16.88 40B Redondo Beach Boulevard   - Redondo Beach Southbound exit and northbound entrance
Lawndale 17.59 42A SR 107 (Hawthorne Boulevard) – Lawndale
Redondo Beach 18.23 42B Inglewood Avenue
Hawthorne 19.21 43 Rosecrans Avenue – Manhattan Beach Signed as exits 43A (east) and 43B (west) southbound
20.22 44 El Segundo Boulevard – El Segundo
Los Angeles R21.18 45A I‑105 (Century Freeway) – El Segundo, Norwalk Signed as exit 45 southbound; serves Los Angeles International Airport; I-105 east exit 2, west exit 2B
R21.22 45B Imperial Highway Southbound exit is part of exit 46
Inglewood 22.22 46 Century Boulevard – LAX Airport
23.36 47 Manchester Boulevard, La Cienega Boulevard, Florence Avenue Manchester Boulevard was former SR 42
Los Angeles 24.27 48 La Tijera Boulevard
24.56 49A Howard Hughes Parkway, Sepulveda Boulevard Signed as exit 49 southbound
Culver City 25.46 49B Sepulveda Boulevard, Slauson Avenue (SR 90 east) Northbound exit only; SR 90 exit 2
25.95 50A Jefferson Boulevard Signed as exit 50B northbound
25.95 50B SR 90 (Marina Freeway) / Slauson Avenue – Marina del Rey Signed as exit 50A northbound; no access from I-405 north to SR 90 east; SR 90 exit 2
27.20 51 Culver Boulevard, Washington Boulevard – Culver City
27.96 52 Venice Boulevard (SR 187), Washington Boulevard
Los Angeles 29.16 53A National Boulevard Northbound exit and southbound entrance
29.54 53B I‑10 (Santa Monica Freeway) – Santa Monica, Los Angeles Signed as exit 53 southbound; I-10 exits 3A-B
30.18 54 Olympic Boulevard, Pico Boulevard Southbound exit and northbound entrance; former SR 26
30.86 55A SR 2 (Santa Monica Boulevard) Former US 66
31.54 55B Wilshire Boulevard Signed as exits 55B (east) and 55C (west) southbound
32.50 56 Montana Avenue Northbound exit only; demolished[32]
33.00 57A Sunset Boulevard Signed as exit 57 southbound
33.29 57B Moraga Drive Northbound exit and entrance
34.76 59 Getty Center Drive
36.03 61 Mulholland Drive, Skirball Center Drive
39.00 63A Ventura Boulevard, Sepulveda Boulevard, Valley Vista Boulevard
39.43 63B US 101 (Ventura Freeway) – Ventura, Los Angeles US 101 exit 19A
40.29 64 Burbank Boulevard
41.36 65 Victory Boulevard – Van Nuys
42.36 66 Sherman Way – Van Nuys Airport Signed as exits 66A (east) and 66B (west) northbound
43.76 68 Roscoe Boulevard – Panorama City
44.74 69 Nordhoff Street
46.24 70 Devonshire Street – Granada Hills
46.85 71A SR 118 (Ronald Reagan Freeway) – Simi Valley Signed as exit 71 southbound; no southbound exit to SR 118 east or northbound entrance from SR 118 west; SR 118 east exit 42A, west exit 42B
47.24 71B San Fernando Mission Boulevard – San Fernando Northbound exit and southbound entrance
47.75 72 Rinaldi Street – Mission Hills
48.64 I‑5 north (Golden State Freeway) – Sacramento Northbound exit and southbound entrance; north end of I-405; I-5 south exit 158
1.000 mi = 1.609 km; 1.000 km = 0.621 mi


  1. ^ a b c California Department of Transportation. "State Truck Route List". Sacramento: California Department of Transportation. Archived from the original ( 
  2. ^ Time For Kids | Classroom | Home | U.S. Highways With the Most Traffic
  3. ^ Santa Monica College Corsair News Article Archived August 15, 2007 at the Wayback Machine
  4. ^ "Most Travelled Urban Highways Average Annual Daily Traffic". 2010-07-27. Retrieved 2013-01-26. 
  5. ^ "CA Codes (shc:250–257)". Retrieved 2013-01-26. 
  6. ^ "Crossroads of Confusion". Los Angeles Times. March 20, 1998. p. 2. Retrieved October 11, 2012. 
  7. ^
  8. ^ Racine, Ned (January 11, 2011). "How the Mulholland Drive bridge was constructed". Los Angeles County Metropolitan Transportation Authority. Retrieved July 16, 2011. 
  9. ^ 2007 Named Freeways, Highways, Structures and Other Appurtenances in California (PDF).  
  10. ^ a b "Interstate 405: The 'Carmageddon', History, Myth and Trivia". During 53 hours of closure, the north side of the Mulholland Bridge will be demolished as part of the $1 billion Sepulveda Pass Improvements Project. 
  11. ^ Judy Gish Issue Date: 06/2011. "Inside Seven - Caltrans, District 7 - Monthly Newsletter". Retrieved 2013-01-26. 
  12. ^ Gostar, Reza (2011-06-09). "Carpocalypse: The Weekend the 405 Freeway Will Stand Still - Brentwood, CA Patch". Retrieved 2013-01-26. 
  13. ^ a b Mather, Kate; Bloomekatz, Ari; Saillant, Saillant (July 19, 2011). "In 'Carmageddon,' some see road map for the future". Los Angeles Times. Retrieved August 1, 2011. 
  14. ^ "Metrolink sets weekend ridership recording during 405 closure". The Source. Retrieved July 21, 2011. 
  15. ^ "JetBlue". JetBlue. Retrieved 2013-01-26. 
  16. ^ "Great Circle Mapper". Retrieved 2013-01-26. 
  17. ^ "LA avoids feared 'Carmageddon' traffic jam". The Independent. July 17, 2011. Retrieved July 17, 2011. 
  18. ^ Morgan, Jared (July 19, 2012). "Carmageddon 2012 Announced, Full 405 Closure in September". Retrieved September 4, 2012. 
  19. ^ "Sepulveda Pass Improvement Project". Los Angeles County Metropolitan Transportation Authority. Retrieved July 15, 2011. 
  20. ^ "LosAngelesMetro comments on Curious about Jamzilla? Ask your questions about the 80hr closure of the northbound 405 and Metro will respond! Join our AMA here on 2/7 from noon to 1pm to ask us anything!". reddit. Retrieved October 4, 2014. 
  21. ^ "LA Time Jamzilla , Feb. 14, 2014". February 14, 2014. Retrieved October 4, 2014. 
  22. ^ "Carpool lane on North 405 Freeway opens". KABC-TV Los Angeles. May 23, 2014. Retrieved May 23, 2014. 
  23. ^ "405 on the move-PR" (PDF). 
  24. ^ "OCTA approves study of 405 widening project". Daily Pilot. February 10, 2010. Retrieved July 16, 2011. 
  25. ^ THE SIMPSON CASE: THE INMATE; Simpson, Under Suicide Watch, Is Jailed on 2 Murder Charges, Seth Mydans, The New York Times, June 19, 1994, Retrieved December 9, 2007
  26. ^ Bill Cosby's Son Is Slain Along Freeway, B. Drummond Ayres Jr., The New York Times, January 17, 1997, Retrieved December 9, 2007
  27. ^ As told in track nine of their iTunes Originals Album
  28. ^ "CLP - Vanity Card #429". Retrieved October 4, 2014. 
  29. ^ California Department of Transportation, Log of Bridges on State Highways, July 2007
  30. ^ California Department of Transportation, All Traffic Volumes on CSHS, 2005 and 2006
  31. ^ California Department of Transportation, California Numbered Exit Uniform System, I-405 Northbound and I-405 Southbound, accessed February 2008
  32. ^ "405 Freeway NB Montana Avenue Offramp Dies At 57". CBS (Los Angeles, California: CBS Radio Inc.). 2013-11-24. Retrieved 2014-03-19. 

External links

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Hawaii eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.