State Route 37 over Simonds Slough
GoodMarin County, California · 04-MRN-037-13.04-NVTO · Structure no. 27 0012
- Built
- 1959
- 66 years old
- Condition
- Good
- inspected May 2024
- Type
- Culvert
- Concrete Continuous
- Length
- 20 ft
- 2 main spans
- Daily traffic
- 34,000
- 2009 count
- Owner
- State
- State Highway Agency
About this bridge
State Route 37 over Simonds Slough is a concrete continuous culvert carrying State Route 37 over Simonds Slough in Marin County, California. It was built in 1959, so it is 66 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 34,000 vehicles a day, roughly 4% of them trucks, projected to reach 54,136 by 2042. The structure is 20 ft (6.2 m) long and 101 ft wide. If it were closed, the detour would be 5 mi (8 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 |
|---|---|---|
| Channel and channel protection | 7 Good | Some minor problems. |
| Culvert | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was State Route 37 over Simonds Slough built?
It was built in 1959, making it 66 years old in 2025.
What condition is State Route 37 over Simonds 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 May 2024.
How much traffic does State Route 37 over Simonds Slough carry?
About 34,000 vehicles per day (2009 count), of which roughly 4% are trucks.
How long is State Route 37 over Simonds Slough?
The structure is 20 ft (6.2 m) long with a longest span of 10 ft (3.1 m) and a deck 101 ft wide.
Who owns State Route 37 over Simonds Slough?
It is owned by the State Highway Agency.