Interstate 405 California
Overview
Following the San Diego Freeway, Interstate 405 is a major highway linking the northern and southern parts of the greater Los Angeles metropolitan area between the San Fernando Valley and Orange County. Always busy, at all hours of the day or night, I-405 is the most direct route between San Diego and Northern California. Additionally, it serves Los Angeles International Airport (LAX) and a number of coastal cities including Costa Mesa, Huntington Beach, Long Beach and Santa Monica.
Mileage by State
| California | 72.42 mi |
Data Sources
December 31, 2025 Interstate Route Log and Finders List
History
Interstate 405 replaced the original route of California State Route 7 through the greater Los Angeles area. Portions of SR 7 were upgraded to a freeway in 1957 and later designated as I-405 by 1963. West of I-605, I-405 was completed before 1965. The stretch of freeway east of I-605 followed by 1969 (Faigin, 2026).
North End 
‐ San Fernando Valley, Los Angeles, CA
North at
Interstate 405 defaults onto I-5 north after the modified diamond interchange (Exit 72) with Rinaldi Street at the Mission Hills community in Los Angeles. 03/06/15
North at
Interstate 5 separates with a truck bypass through the wye interchange at the north end of I-405. The outside roadway returns to I-5 ahead of the exchange with Interstate 210 (Foothill Freeway). 07/07/15
South at
Interchange sequence sign outlining the succeeding ramps along I-5 southbound for Exit 159 / Roxford Street, the truck bypass for I-5/405 and the San Diego Freeway mainline at Exit 158. 07/10/22
North End – Past Views
Past Views Gallery (Tap to Expand / Collapse Section)
South at
Replaced by Fall 2016, this porcelain enamel was the first referencing Interstate 405 on I-5 south. 07/07/13
South End ‐ Irvine, CA
South at
Exit 1 B to Bake Parkway extends south along the commercialized west side of Interstate 5 (Santa Ana Freeway) to Bake Parkway. Interstate 405 (San Diego Freeway) converges with I-5 at a wye interchange in one half mile. 06/17/06
North at
Travelers along Interstate 5 (San Diego Freeway) northbound may use the high occupancy vehicle (HOV) lanes, the main lanes, or truck lanes to connect with I-405 north at Exit 94 A. 07/09/18
Truck Bypass Lanes North at
Four lanes lead north along the I-5 Truck Bypass roadway from Lake Forest Drive to the parclo A2 interchange with Bake Parkway. A left exit for Interstate 405 (San Diego Freeway) follows. 07/13/09
South End – Past Views
Past Views Gallery (Tap to Expand / Collapse Section)
North at
I-5 north at the separation with I-405 prior to the addition of exit numbers for the San Diego Freeway. 03/25/05
