Trancas ST over Milliken Creek
FairNapa County, California · Just West of SR 121 · Structure no. 21C0026
- Built
- 1973
- 52 years old
- Condition
- Fair
- inspected May 2024
- Type
- Tee Beam
- Concrete Continuous
- Length
- 99 ft
- 2 main spans
- Daily traffic
- 9,000
- 2012 count
- Owner
- County
- County Highway Agency
About this bridge
Trancas ST over Milliken Creek is a concrete continuous tee beam carrying Trancas ST over Milliken Creek in Napa County, California. It was built in 1973, so it is 52 years old, younger than the California average of 54.8 years.
The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
It carries about 9,000 vehicles a day, roughly 10% of them trucks, projected to reach 33,812 by 2046. The structure is 99 ft (30.2 m) long and 57 ft wide. If it were closed, the detour would be 3.7 mi (6 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 6 Satisfactory | Structural elements show some minor deterioration. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Trancas ST over Milliken Creek built?
It was built in 1973, making it 52 years old in 2025.
What condition is Trancas ST over Milliken Creek in?
The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in May 2024.
How much traffic does Trancas ST over Milliken Creek carry?
About 9,000 vehicles per day (2012 count), of which roughly 10% are trucks.
How long is Trancas ST over Milliken Creek?
The structure is 99 ft (30.2 m) long with a longest span of 49 ft (14.9 m) and a deck 57 ft wide.
Who owns Trancas ST over Milliken Creek?
It is owned by the County Highway Agency.