Interstate 405 is the designation of three different tertiary interstate routes of Interstate 5.

Table of contents
1 California
2 Washington
3 Oregon

California

Interstate 405 in southern California, also known as the San Diego Freeway, is a loop branch of the I-5 extending from Laguna Hills, California, up through Orange County, California and Los Angeles, and rejoining the I-5 in the San Fernando Valley. The freeway is one of the most famous in the nation for "bumper to bumper" traffic. For Los Angeles, which relies on freeways for most transportation, the 405 is a central artery on which many Angelenos travel every day.

Major cities and suburbs

Washington

Interstate 405 in Washington state is a loop route that bypasses downtown Seattle east of Lake Washington. The northern terminus is in Lynnwood and the southern terminus is in Tukwila.

Major cities and suburbs

Oregon

Interstate 405 in Oregon is a short loop route that connects downtown Portland west of the Willamette River to Interstate 5. I-405 only travels through the city of Portland.

See Interstate 5