Mapes Lane RD 305 over Susan River Overflow #4
FairLassen County, California · 1.3 MI E of RD 304 · Structure no. 07C0042
- Built
- 2000
- 25 years old
- Condition
- Fair
- inspected August 2024
- Type
- Slab
- Concrete Continuous
- Length
- 60 ft
- 3 main spans
- Daily traffic
- 100
- 1979 count
- Owner
- County
- County Highway Agency
About this bridge
Mapes Lane RD 305 over Susan River Overflow #4 is a concrete continuous slab carrying Mapes Lane RD 305 over Susan River Overflow #4 in Lassen County, California. It was built in 2000, so it is 25 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 100 vehicles a day, roughly 5% of them trucks, projected to reach 170 by 2046. The structure is 60 ft (18.3 m) long and 27 ft wide. If it were closed, the detour would be 11.8 mi (19 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 | 6 Satisfactory | Structural elements show some minor deterioration. |
| 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 Mapes Lane RD 305 over Susan River Overflow #4 built?
It was built in 2000, making it 25 years old in 2025.
What condition is Mapes Lane RD 305 over Susan River Overflow #4 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 August 2024.
How much traffic does Mapes Lane RD 305 over Susan River Overflow #4 carry?
About 100 vehicles per day (1979 count), of which roughly 5% are trucks.
How long is Mapes Lane RD 305 over Susan River Overflow #4?
The structure is 60 ft (18.3 m) long with a longest span of 20 ft (6.1 m) and a deck 27 ft wide.
Who owns Mapes Lane RD 305 over Susan River Overflow #4?
It is owned by the County Highway Agency.