Structure 28 0100 · Contra Costa County, CA
Carries Interstate 580 over San Pablo Bay, 04-cc-580-6.22-rch.
Set by its lowest-rated component: Superstructure and Substructure at 5 of 9.
How ratings work21,345 ft end to end, longest span 1,087 ft: about 59 football fields, or 4.0 miles. 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 through truss.
| State | California |
| County | Contra Costa |
| Location | 04-cc-580-6.22-rch |
| Carries | Interstate 580 |
| Crosses | San Pablo Bay |
| Coordinates | 37.93262, -122.40533 |
| Material | Steel |
| Design | Truss - Thru |
| Total Length | 21345.1 ft (6,506 m) |
| Max Span | 1086.9 ft (331.3 m) |
| Deck Width | 78.1 ft (23.8 m) |
| Deck Area | 154842.8 sq m |
| Main Spans | 6 |
| Year Built | 1956 |
| Avg Daily Traffic | 78,000 (2022) |
| Truck Traffic | 5% |
| Lanes On Bridge | 5 |
| Last Inspection | December 2024 |
| Inspection Frequency | Every 24 months |
| Owner | State Highway Agency |
| Historical Significance | Bridge is eligible for the National Register |
| Scour Critical | 5 — Stable for scour |
| Structure Number | 28 0100 |
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.