INTERSTATE 405
INTERSTATE 405 in 12-Ora-405-18.36-Wtm, Orange County, California received a condition grade of B (72/100). Built in 1965, the bridge carries 256K vehicles daily on INTERSTATE 405 over Navy RR Spur.
INTERSTATE 405 carries a B on the BridgeSafety Condition Score with 72/100. Most component ratings are solid; one or two may show wear consistent with the structure’s age, but the bridge is not flagged as structurally deficient.
The bridge was built in 1965 and is now 61 years old, at or past the typical 50-year design life for bridges of its vintage. Maintenance and inspection cycles are correspondingly more involved than for newer structures. INTERSTATE 405 carries an average daily traffic count of 256,000 vehicles, with 10 lane(s) crossing Navy RR Spur. The owning agency is State Highway Agency; bridge inspection records flow into the federal NBI database annually.
Component Ratings
The riding surface, evaluated for cracking, spalling, and wear
Beams, girders, and trusses that support the deck
Piers, abutments, and foundations below the deck
Bridge Details
About This Bridge
INTERSTATE 405 is a 61-year-old bridge located 12-Ora-405-18.36-Wtm in Orange County, California. The bridge carries INTERSTATE 405 over Navy RR Spur with 10 traffic lanes, handling approximately 256K vehicles per day. Built in 1965 and reconstructed in 1989, the structure spans 53.9 meters.
The bridge received a Condition Grade of B (72/100) based on Federal Highway Administration inspection data. Its deck is rated 7/9 (good), superstructure 7/9 (good), and substructure 7/9 (good).
This bridge is owned and maintained by State Highway Agency.
Location Map
Frequently Asked Questions
INTERSTATE 405 has a Condition Score of 72/100 (Grade B). Its deck is rated 7/9, superstructure 7/9, and substructure 7/9 on the NBI scale. The bridge is not classified as structurally deficient.
INTERSTATE 405 was built in 1965 and reconstructed in 1989, making it 61 years old. The average bridge age in the United States is 48 years.
INTERSTATE 405 carries approximately 256K vehicles per day (average daily traffic). The bridge has 10 traffic lanes. It is 53.9 meters long and located on INTERSTATE 405 in 12-Ora-405-18.36-Wtm, Orange County, California.
No, INTERSTATE 405 is not classified as structurally deficient. All three primary components (deck, superstructure, and substructure) are rated above 4 on the 0-9 NBI scale.
INTERSTATE 405 is located 12-Ora-405-18.36-Wtm in Orange County, California. The bridge carries INTERSTATE 405 over Navy RR Spur. Its coordinates are 33.750850, -118.011867. It is maintained by State Highway Agency.
INTERSTATE 405 carries INTERSTATE 405 over Navy RR Spur. The bridge is 53.9 meters long and was built in 1965, with reconstruction in 1989.
Condition Score is calculated from deck (33%), superstructure (33%), and substructure (34%) NBI ratings with an age penalty for bridges over 50 years.
Source: FHWA National Bridge Inventory, 2026.