HWY 312 over RR
FairYellowstone County, Montana · 1M W Pompey`s Pillar · Structure no. S00568000+00621
- Built
- 2004
- 21 years old
- Condition
- Fair
- inspected March 2023
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete Continuous
- Length
- 318 ft
- 3 main spans
- Daily traffic
- 401
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
HWY 312 over RR is a prestressed concrete continuous stringer/multi-beam or girder carrying HWY 312 over RR in Yellowstone County, Montana. It was built in 2004, so it is 21 years old, younger than the Montana average of 47 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 401 vehicles a day, roughly 7% of them trucks, projected to reach 421 by 2043. The structure is 318 ft (97 m) long and 34 ft wide. If it were closed, the detour would be 9.9 mi (16 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 | 7 Good | Some minor problems. |
| Substructure | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was HWY 312 over RR built?
It was built in 2004, making it 21 years old in 2025.
What condition is HWY 312 over RR 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 March 2023.
How much traffic does HWY 312 over RR carry?
About 401 vehicles per day (2023 count), of which roughly 7% are trucks.
How long is HWY 312 over RR?
The structure is 318 ft (97 m) long with a longest span of 144 ft (43.8 m) and a deck 34 ft wide.
Who owns HWY 312 over RR?
It is owned by the State Highway Agency.