Los Trancos Rd over Los Trancos Creek
San Mateo County, California · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Los Trancos Rd over Los Trancos Creek in San Mateo County, California, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 7 (good condition) on the 0-9 scale.
- It was built in 1989, making it 36 years old at the 2025 inventory.
- It carries about 2,700 vehicles a day (traffic count year 2018).
- Its listed owner is a city or municipal highway agency.
- It is one of 100 of the 361 inventoried bridges in San Mateo County rated good (27.7%); 37 (10.2%) are rated poor.
- A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.
View this bridge on a map → (37.36283, -122.20238)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Culvert | 7 | Good condition |
Bridge details
| Structure | Concrete culvert |
| Length | about 22 ft |
| Location | 1.5 Mi S Alpine Rd |
| NBI structure number | 35C0171 |
| Condition class | Good |
Source: FHWA National Bridge Inventory, 2025 data as reported by the California department of transportation.
Busiest bridges in San Mateo County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| U.S. Highway 101 over San Mateo Creek | 1928 | 236,000 | Good |
| US 101 Rollins Rd over Transmission Canal | 1928 | 232,000 | Fair |
| US 101 Mcdonnell over Millbrae Slough | 1947 | 226,000 | Fair |
| US 101 W&e Bayshr over San Francisquito Creek | 2018 | 225,800 | Good |
| Holly Street over US Highway 101 | 1954 | 201,000 | Fair |
| Whipple Avenue over US Highway 101 | 1958 | 201,000 | Good |
All bridges nearby: San Mateo County, CA bridge conditions · every bridge in San Mateo County · California bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.