History of Interstate 405 in California

By | October 14, 2022

Interstate 405 was approved in 1955. The first section opened at Santa Monica in 1957, and the section between Long Beach and I-5 in the San Fernando Valley was completed in 1963. After that, it was mainly built in Orange County. The last section of I-405 was the southernmost section through Irvine that opened on December 9, 1968. The section between I-10 and I-5 between Santa Monica and San Fernando was formerly known as the “Sepulveda Freeway,” named for the parallel street. The highway was made famous by OJ Simpson’s pursuit in 1994.

Later adjustments

Sepulveda Pass

In 2002, an HOV lane was constructed on I-405 heading south from US 101 to I-10. This was the first substantial modification to I-405 since the 1960s.

Between the spring of 2009 and May 2014 , a 16 kilometer long HOV lane was constructed on I-405 between I-10 and US 101 heading north. This made a through HOV lane available on I-405 in both directions. The northbound carriageway has been widened from 5 to 6 lanes. Construction costs were $1,340 million.

West County Connectors

According to Topschoolsintheusa, the ‘West County Connectors’ project has been completed on the busiest stretch of road at Seal Beach, which includes additional flyovers for the car pool lanes at the interchanges with I-605 in Long Beach and SR-22 in Garden Grove. The I-405 has also been widened to 2×8 lanes here. On November 7, 2014, the first ‘connector’ opened at the interchange of I-405 with SR-22 towards Garden Grove. The entire project was completed in December 2014.

Opening history

Van Unpleasant Length Opening
Ohio Avenue Sunset Blvd 3 km 28-03-1957
Venice Blvd Ohio Ave 5 km 26-01-1959
Jefferson Blvd Venice Blvd 3 km 24-06-1960
I-710 Alameda St 2 km 22-01-1962
Hawthorne Blvd the second blvd 4 km 00-05-1962
Alameda St Western Ave 9 km 00-07-1962
Western Avenue Hawthorne Blvd 5 km 13-08-1962
Sunset Blvd Valley Vista Blvd 9 km 21-12-1962
Valley Vista Blvd Burbank Blvd 3 km 00-04-1963
Burbank Blvd I-5 14 km 19-04-1963
the second blvd Jefferson Blvd 9 km 10-06-1963
Altantic Ave I-710 2 km 15-01-1964
Greater Garden Grove Atlantic Ave 14 km 30-09-1964
Beach Blvd Greater Garden Grove 7 km 02-11-1965
Harbor Blvd Beach Blvd 8 km 11-11-1966
Jamboree Road Harbor Blvd 4 km 00-04-1967
I-5 Jamboree Road 12 km 09-12-1968


Orange County

It is planned to widen I-405 in Orange County, between State Route 22 in Rossmoor and State Route 73 in Costa Mesa. Without measures, the travel time on this route would increase to 133 minutes. With the preferred alternative, this becomes 13 to 29 minutes. The preferred alternative is the addition of one express lane with toll collection, and one general purpose lane per direction. Where now HOV lanesthese will be integrated with the express lanes, so that there are two express lanes in each direction, with free use by HOV2+ carpoolers. The existing dual HOV lanes of I-405 between I-605 and SR-22 will be incorporated as express lanes. This part already has 16 lanes and will get a seventh GP lane in each direction, so that a total of 18 lanes will be located along Seal Beach. The rest of the route will be widened to predominantly 14 lanes. The cost of this project is estimated at $1.9 billion. The record of decision was established in May 2015. A $1.2 billion contract was awarded on November 14, 2016. [24] Work started on January 26, 2018. [25] [26]The project should open in mid-2023, construction time is estimated at 54 months (4.5 years). The expected traffic intensity on the route is between 348,000 and 503,000 vehicles per day.


Beginning in 2013, the entirety of I-405 will have continuous HOV lanes in both directions, making it the longest continuous HOV facility in the United States, spanning nearly 75 miles. With connecting road sections of the I-5, the HOV lanes can even be used continuously for 200 kilometers from San Clemente to Palmdale. The I-405 HOV lanes were largely created by converting the left hard shoulder into an HOV lane.


I-405’s oldest HOV lane opened in January 1989 in Orange County from SR-73 in Costa Mesa to I-605 in Long Beach. At the time, this was also one of the longest HOV facilities in the country. In May 1991, HOV lanes opened further from El Toro Y with I-5 in Irvine to SR-73 in Costa Mesa, making I-405 the first freeway in Orange County to have through-hole HOV lanes.

On April 8, 1993, the first HOV lane in Los Angeles County opened from I-110 to El Segundo. In January 1994, these HOV lanes were extended north to Century City. On October 22, 1996, the northernmost HOV lanes opened between US 101 and I-5 in the San Fernando Valley. Then, on February 12, 1998, HOV lanes opened from Orange County to I-710 in Long Beach, and continued to I-110 on October 8, 1998, completing the HOV lanes in Los Angeles County on the Sepulveda Pass stretch. used to be. In 2002 and 2007, the HOV lane between US 101 and I-10 south was opened. In 2013, the HOV lane will open to the north, giving the entire I-405 HOV lanes.

Traffic intensities

I-405 at the interchange with State Route 22.

Exit Location 2008 2012 2016
Exit 1 Irvine (I-5) 190.000 190.000 190.000
Exit 2 Irvine (SR-133) 237.000 249.000 250.000
Exit 9 Coast Table ( SR-55 ) 274.000 280.000 279.000
Exit 12 Fountain Valley 310.000 313.000 312.000
Exit 21 Seal Beach (SR-22) 374.000 378.000 377.000
Exit 24 Long Beach (I-605) 253.000 255.000 255.000
Exit 32 Long Beach (I-710) 282.000 282.000 281.000
Exit 37 Long Beach (I-110) 267.000 266.000 275.000
Exit 45 Inglewood (I-105) 302.000 313.000 327.000
Exit 47 Inglewood 311.000 323.000 324.000
Exit 50 Culver City (SR-90) 286.000 310.000 322.000
Exit 53 Los Angeles (I-10) 275.000 295.000 309.000
Exit 55 Los Angeles ( SR-2 ) 303.000 317.000 310.000
Exit 63 Los Angeles (US 101) 281.000 278.000 288.000
Exit 71 Los Angeles ( SR-118 ) 215.000 212.000 215.000
Exit 72 Los Angeles (I-5) 137.000 137.000 146.000


I-405 is one of the most congested highways in the United States. The entire highway is extremely congested, with more than 300,000 vehicles per day traveling in 2×5 lanes on many stretches, causing heavy congestion at many points throughout the day.

Heading south, it often jams before the interchange with US 101, and in both directions near Interstate 10 and the LAX Airport. Also, the part along Long Beach is very busy, as is the part before the Garden Grove Freeway, also the busiest highway in the United States.

Northbound I-405 between I-105 and Getty Center Drive is the third largest congestion bottleneck in the United States. The number of hours lost here was 965,000 per mile in 2010. It is also the second largest cause of unnecessarily consumed fuel, with 23 million liters of fuel being used unnecessarily. It is also the second most expensive traffic jam in the country with an annual loss of $270 million.

I-405 heading south, between Nordhoff Street in the San Fernando Valley and Mulholland Drive on the Sepulveda Pass, is the largest morning rush hour traffic jam in the United States, with a 365,000 hour-per-mile delay in 2010. This morning rush hour traffic jam costs $63 million per year.

Lane Configuration

HOV lanes including, excluding weaving areas, and non-through parallel systems.

Van Unpleasant Lanes length
0 7 Jamboree Road 2×5 12 km
7 Jamboree Road 10 2×6 5 km
10 14 Brookhurst Street 2×7 6 km
14 Brookhurst Street 21 2×5 12 km
21 24A 2×8 5 km
24A 37A 2×5 21 km
37A 38B Western Avenue 2×4 2 km
38B Western Avenue 50B 2×5 19 km
50B 63B 2×6 21 km
63B 71A 2×5 13 km
71A 73 2×3 3 km

History of Interstate 405 in California