STATE ROUTE 55
STATE ROUTE 55 in 12-Ora-055-13.42-Ora, Orange County, California received a condition grade of B (63/100). Built in 1962, the bridge carries 248K vehicles daily on STATE ROUTE 55 over Santiago Creek.
STATE ROUTE 55 carries a B on the BridgeSafety Condition Score with 63/100. 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 1962 and is now 64 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. STATE ROUTE 55 carries an average daily traffic count of 248,000 vehicles, with 13 lane(s) crossing Santiago Creek. 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
STATE ROUTE 55 is a 64-year-old bridge located 12-Ora-055-13.42-Ora in Orange County, California. The bridge carries STATE ROUTE 55 over Santiago Creek with 13 traffic lanes, handling approximately 248K vehicles per day. Built in 1962 and reconstructed in 2002, the structure spans 111.7 meters.
The bridge received a Condition Grade of B (63/100) based on Federal Highway Administration inspection data. Its deck is rated 5/9 (fair), superstructure 7/9 (good), and substructure 7/9 (good).
This bridge is owned and maintained by State Highway Agency.
Location Map
Frequently Asked Questions
STATE ROUTE 55 has a Condition Score of 63/100 (Grade B). Its deck is rated 5/9, superstructure 7/9, and substructure 7/9 on the NBI scale. The bridge is not classified as structurally deficient.
STATE ROUTE 55 was built in 1962 and reconstructed in 2002, making it 64 years old. The average bridge age in the United States is 48 years.
STATE ROUTE 55 carries approximately 248K vehicles per day (average daily traffic). The bridge has 13 traffic lanes. It is 111.7 meters long and located on STATE ROUTE 55 in 12-Ora-055-13.42-Ora, Orange County, California.
No, STATE ROUTE 55 is not classified as structurally deficient. All three primary components (deck, superstructure, and substructure) are rated above 4 on the 0-9 NBI scale.
STATE ROUTE 55 is located 12-Ora-055-13.42-Ora in Orange County, California. The bridge carries STATE ROUTE 55 over Santiago Creek. Its coordinates are 33.783881, -117.830728. It is maintained by State Highway Agency.
STATE ROUTE 55 carries STATE ROUTE 55 over Santiago Creek. The bridge is 111.7 meters long and was built in 1962, with reconstruction in 2002.
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.