State Route 99 NB over Willow Slough
GoodSacramento County, California · 03-SAC-099-6.54 · Structure no. 24 0046R
- Built
- 1958
- 67 years old, rebuilt 1993
- Condition
- Good
- inspected July 2024
- Type
- Slab
- Concrete Continuous
- Length
- 60 ft
- 3 main spans
- Daily traffic
- 31,500
- 2019 count
- Owner
- State
- State Highway Agency
About this bridge
State Route 99 NB over Willow Slough is a concrete continuous slab carrying State Route 99 NB over Willow Slough in Sacramento County, California. It was built in 1958 and reconstructed in 1993, so it is 67 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 31,500 vehicles a day, roughly 18% of them trucks, projected to reach 55,865 by 2046. The structure is 60 ft (18.4 m) long and 42 ft wide. If it were closed, the detour would be 8.1 mi (13 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 | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was State Route 99 NB over Willow Slough built?
It was built in 1958, making it 67 years old in 2025. It was reconstructed in 1993.
What condition is State Route 99 NB over Willow Slough 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 July 2024.
How much traffic does State Route 99 NB over Willow Slough carry?
About 31,500 vehicles per day (2019 count), of which roughly 18% are trucks.
How long is State Route 99 NB over Willow Slough?
The structure is 60 ft (18.4 m) long with a longest span of 20 ft (6.1 m) and a deck 42 ft wide.
Who owns State Route 99 NB over Willow Slough?
It is owned by the State Highway Agency.