I-405 (CA)

Interstate 405
San Diego Freeway
Route information
Defined by
Maintained by Caltrans
Length:	72.415 mi (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
Interstate Highway System Main Auxiliary Suffixed Business Future State highways in California Interstate U.S. State Pre-1964 History Unconstructed Deleted Freeway Scenic ← US 395 US 466 →

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 longer route than using Interstate 5, running along the scenic 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. 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. It has played a crucial role in the development of dozens of cities and suburbs along its route through Los Angeles and Orange counties.

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

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.

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Wikipedia