Alexander Ave over Bunker Road
Marin County, California · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Alexander Ave over Bunker Road in Marin County, California, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the substructure, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1937, making it 88 years old at the 2025 inventory.
- It carries about 7,201 vehicles a day (traffic count year 2024).
- It is one of 100 of the 207 inventoried bridges in Marin County rated fair (48.3%); 16 (7.7%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- It was rated poor in the 2024 inventory and is now fair (superstructure 4 to 6).
- Its most recent inspection on record is dated March 2024, on a 24-month routine inspection cycle.
- A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.
View this bridge on a map → (37.83801, -122.48303)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Superstructure | 4 | 6 | Satisfactory condition |
| Substructure | 5 | 5 | Fair condition |
Bridge details
| Structure | Concrete deck arch |
| Length | about 32 ft |
| Location | 0.3 Km East of Rte 101 |
| NBI structure number | 27C0053 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | March 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | N: not over a waterway |
Source: FHWA National Bridge Inventory, 2025 data as reported by the California department of transportation.
Busiest bridges in Marin County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US Highway 101 over North San Pedro Road | 1979 | 180,000 | Fair |
| U.S. Highway 101 over Lincoln Ave-n101 on Ramp | 1938 | 180,000 | Fair |
| U.S. Highway 101 over Linden Lane | 1947 | 173,000 | Good |
| U.S. Highway 101 over Ggt Bellam Andersen | 1958 | 172,000 | Good |
| U.S. Highway 101 over Corte Madera CR & Sfd Bl | 1957 | 172,000 | Fair |
| U.S. Highway 101 over Wornum Drive | 1929 | 172,000 | Good |
All bridges nearby: Marin County, CA bridge conditions · every bridge in Marin County · California bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.