Mill Station RD over Atascadero CR Overflow
PoorSonoma County, California · 0.2 MI E Ferguson RD · Structure no. 20C0315
- Built
- 1964
- 61 years old
- Condition
- Poor
- inspected February 2025
- Type
- Slab
- Concrete Continuous
- Length
- 95 ft
- 4 main spans
- Daily traffic
- 1,450
- 2018 count
- Owner
- County
- County Highway Agency
About this bridge
Mill Station RD over Atascadero CR Overflow is a concrete continuous slab carrying Mill Station RD over Atascadero CR Overflow in Sonoma County, California. It was built in 1964, so it is 61 years old, older than the California average of 54.8 years.
The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
It carries about 1,450 vehicles a day, roughly 1% of them trucks, projected to reach 1,916 by 2043. The structure is 95 ft (29 m) long and 32 ft wide. If it were closed, the detour would be 3.1 mi (5 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Superstructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Substructure | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
| Channel and channel protection | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Mill Station RD over Atascadero CR Overflow built?
It was built in 1964, making it 61 years old in 2025.
What condition is Mill Station RD over Atascadero CR Overflow in?
The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in February 2025.
How much traffic does Mill Station RD over Atascadero CR Overflow carry?
About 1,450 vehicles per day (2018 count), of which roughly 1% are trucks.
How long is Mill Station RD over Atascadero CR Overflow?
The structure is 95 ft (29 m) long with a longest span of 27 ft (8.1 m) and a deck 32 ft wide.
Who owns Mill Station RD over Atascadero CR Overflow?
It is owned by the County Highway Agency.