Structure 55 0259 · Orange County, CA
Carries Interstate 405 over Service Road, 12-ora-405-12.40-cms.
Set by its lowest-rated component: Deck and Superstructure and Substructure at 7 of 9.
How ratings work21 ft end to end. Lengths are drawn to scale; at this length a semi-truck would be a speck. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a slab bridge.
| State | California |
| County | Orange |
| Location | 12-ora-405-12.40-cms |
| Carries | Interstate 405 |
| Crosses | Service Road |
| Coordinates | 33.69543, -117.93378 |
| Material | Concrete |
| Design | Slab |
| Total Length | 21.0 ft (6.4 m) |
| Max Span | 19.0 ft (5.8 m) |
| Deck Width | 202.1 ft (61.6 m) |
| Deck Area | 394.2 sq m |
| Main Spans | 1 |
| Year Built | 1966 (reconstructed 2001) |
| Avg Daily Traffic | 300,000 (2014) |
| Truck Traffic | 6% |
| Lanes On Bridge | 14 |
| Last Inspection | August 2023 |
| Inspection Frequency | Every 24 months |
| Owner | State Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Scour Critical | Not applicable |
| Structure Number | 55 0259 |
Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."
A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.