Willow Pass RD over Mt Diablo Crk
GoodContra Costa County, California · 0.8 MI S of SH 4 · Structure no. 28C0034
- Built
- 1944
- 81 years old
- Condition
- Good
- inspected January 2025
- Type
- Slab
- Concrete Continuous
- Length
- 1,067 ft
- 32 main spans
- Daily traffic
- 7,200
- 1977 count
- Owner
- City
- City or Municipal Highway Agency
About this bridge
Willow Pass RD over Mt Diablo Crk is a concrete continuous slab carrying Willow Pass RD over Mt Diablo Crk in Contra Costa County, California. It was built in 1944, so it is 81 years old, older than the California average of 54.8 years.
The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
It carries about 7,200 vehicles a day, roughly 7% of them trucks, projected to reach 24,471 by 2047. The structure is 1,067 ft (325.2 m) long and 32 ft wide. If it were closed, the detour would be 16.2 mi (26 km).
Location
Open in Google MapsCondition and inspection
All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 9 Excellent | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Willow Pass RD over Mt Diablo Crk built?
It was built in 1944, making it 81 years old in 2025.
What condition is Willow Pass RD over Mt Diablo Crk in?
The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in January 2025.
How much traffic does Willow Pass RD over Mt Diablo Crk carry?
About 7,200 vehicles per day (1977 count), of which roughly 7% are trucks.
How long is Willow Pass RD over Mt Diablo Crk?
The structure is 1,067 ft (325.2 m) long with a longest span of 40 ft (12.2 m) and a deck 32 ft wide.
Who owns Willow Pass RD over Mt Diablo Crk?
It is owned by the City or Municipal Highway Agency.