BridgeSafety
Orange County, CA · Structure #55 0506

STATE ROUTE 91

STATE ROUTE 91 in 12-Ora-091-R16.40-Ana, Orange County, California received a condition grade of B (75/100). Built in 1971, the bridge carries 290K vehicles daily on STATE ROUTE 91 over Gypsum Canyon RD.

STATE ROUTE 91 carries a B on the BridgeSafety Condition Score with 75/100. 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 1971 and is now 55 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 91 carries an average daily traffic count of 290,000 vehicles, with 14 lane(s) crossing Gypsum Canyon RD. The owning agency is State Highway Agency; bridge inspection records flow into the federal NBI database annually.

B
75/100
75
Condition Score
290K
Daily Traffic
1971
Year Built
39.3m
Length

Component Ratings

DeckGood
7/9

The riding surface, evaluated for cracking, spalling, and wear

SuperstructureGood
7/9

Beams, girders, and trusses that support the deck

SubstructureGood
7/9

Piers, abutments, and foundations below the deck

Bridge Details

Road
STATE ROUTE 91
Crosses Over
Gypsum Canyon RD
State
California
County
Orange County
Location
12-Ora-091-R16.40-Ana
Year Built
1971
Reconstructed
1994
Age
55 years
Daily Traffic
290,000
Lanes
14
Length
39.3 meters
Owner
State Highway Agency
Structure Number
55 0506

About This Bridge

STATE ROUTE 91 is a 55-year-old bridge located 12-Ora-091-R16.40-Ana in Orange County, California. The bridge carries STATE ROUTE 91 over Gypsum Canyon RD with 14 traffic lanes, handling approximately 290K vehicles per day. Built in 1971 and reconstructed in 1994, the structure spans 39.3 meters.

The bridge received a Condition Grade of B (75/100) 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

12-Ora-091-R16.40-Ana, Orange County, California

33.866539, -117.711592

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Frequently Asked Questions

STATE ROUTE 91 has a Condition Score of 75/100 (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.

STATE ROUTE 91 was built in 1971 and reconstructed in 1994, making it 55 years old. The average bridge age in the United States is 48 years.

STATE ROUTE 91 carries approximately 290K vehicles per day (average daily traffic). The bridge has 14 traffic lanes. It is 39.3 meters long and located on STATE ROUTE 91 in 12-Ora-091-R16.40-Ana, Orange County, California.

No, STATE ROUTE 91 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 91 is located 12-Ora-091-R16.40-Ana in Orange County, California. The bridge carries STATE ROUTE 91 over Gypsum Canyon RD. Its coordinates are 33.866539, -117.711592. It is maintained by State Highway Agency.

STATE ROUTE 91 carries STATE ROUTE 91 over Gypsum Canyon RD. The bridge is 39.3 meters long and was built in 1971, with reconstruction in 1994.

Last updated:

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.