INTERSTATE 605
INTERSTATE 605 in 12-Ora-605-R0.16-Lalm, Orange County, California received a condition grade of B (73/100). Built in 1966, the bridge carries 185K vehicles daily on INTERSTATE 605 over E22-N405 Connector Ramp.
INTERSTATE 605 carries a B on the BridgeSafety Condition Score with 73/100. 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 1966 and is now 60 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 605 carries an average daily traffic count of 185,000 vehicles, with 6 lane(s) crossing E22-N405 Connector Ramp. 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 605 is a 60-year-old bridge located 12-Ora-605-R0.16-Lalm in Orange County, California. The bridge carries INTERSTATE 605 over E22-N405 Connector Ramp with 6 traffic lanes, handling approximately 185K vehicles per day. Built in 1966, the structure spans 10.4 meters.
The bridge received a Condition Grade of B (73/100) 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 605 has a Condition Score of 73/100 (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 605 was built in 1966, making it 60 years old. The average bridge age in the United States is 48 years.
INTERSTATE 605 carries approximately 185K vehicles per day (average daily traffic). The bridge has 6 traffic lanes. It is 10.4 meters long and located on INTERSTATE 605 in 12-Ora-605-R0.16-Lalm, Orange County, California.
No, INTERSTATE 605 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 605 is located 12-Ora-605-R0.16-Lalm in Orange County, California. The bridge carries INTERSTATE 605 over E22-N405 Connector Ramp. Its coordinates are 33.786139, -118.090469. It is maintained by State Highway Agency.
INTERSTATE 605 carries INTERSTATE 605 over E22-N405 Connector Ramp. The bridge is 10.4 meters long and was built in 1966.
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.