SR 55
SR 55 in 12-Ora-055-R5.89-Cms, Orange County, California received a condition grade of B (62/100). Built in 1966, the bridge carries 167K vehicles daily on SR 55 over S405-N55 Connector. It is classified as structurally deficient.
SR 55 carries a B on the BridgeSafety Condition Score with 62/100. 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. SR 55 carries an average daily traffic count of 167,000 vehicles, with 10 lane(s) crossing S405-N55 Connector. 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
SR 55 is a 60-year-old bridge located 12-Ora-055-R5.89-Cms in Orange County, California. The bridge carries SR 55 over S405-N55 Connector with 10 traffic lanes, handling approximately 167K vehicles per day. Built in 1966 and reconstructed in 1970, the structure spans 42.4 meters.
The bridge received a Condition Grade of B (62/100) based on Federal Highway Administration inspection data. Its deck is rated 4/9 (poor), superstructure 7/9 (good), and substructure 7/9 (good). The bridge is classified as structurally deficient, meaning at least one major component is rated 4 or below, this signals a need for repair or replacement but does not necessarily indicate an immediate safety hazard.
This bridge is owned and maintained by State Highway Agency.
Location Map
Frequently Asked Questions
SR 55 has a Condition Score of 62/100 (Grade B). Its deck is rated 4/9, superstructure 7/9, and substructure 7/9 on the NBI scale. The bridge is classified as structurally deficient.
SR 55 was built in 1966 and reconstructed in 1970, making it 60 years old. The average bridge age in the United States is 48 years.
SR 55 carries approximately 167K vehicles per day (average daily traffic). The bridge has 10 traffic lanes. It is 42.4 meters long and located on SR 55 in 12-Ora-055-R5.89-Cms, Orange County, California.
Yes, SR 55 is classified as structurally deficient because at least one of its primary components (deck, superstructure, or substructure) is rated 4 or below on the 0-9 NBI scale. This does not necessarily mean it is unsafe, but it requires significant repair or replacement.
SR 55 is located 12-Ora-055-R5.89-Cms in Orange County, California. The bridge carries SR 55 over S405-N55 Connector. Its coordinates are 33.685981, -117.873183. It is maintained by State Highway Agency.
SR 55 carries SR 55 over S405-N55 Connector. The bridge is 42.4 meters long and was built in 1966, with reconstruction in 1970.
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.