I 315S over Int I 15
FairCascade County, Montana · Great Falls · Structure no. I00315000+00001
- Built
- 1967
- 58 years old
- Condition
- Fair
- inspected October 2024
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 298 ft
- 5 main spans
- Daily traffic
- 12,651
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
I 315S over Int I 15 is a prestressed concrete stringer/multi-beam or girder carrying I 315S over Int I 15 in Cascade County, Montana. It was built in 1967, so it is 58 years old, older 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 12,651 vehicles a day, roughly 5% of them trucks, projected to reach 13,284 by 2043. The structure is 298 ft (90.7 m) long and 54 ft wide.
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 | 7 Good | Some minor problems. |
| Superstructure | 8 Very Good | No problems noted. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was I 315S over Int I 15 built?
It was built in 1967, making it 58 years old in 2025.
What condition is I 315S over Int I 15 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 October 2024.
How much traffic does I 315S over Int I 15 carry?
About 12,651 vehicles per day (2023 count), of which roughly 5% are trucks.
How long is I 315S over Int I 15?
The structure is 298 ft (90.7 m) long with a longest span of 72 ft (21.8 m) and a deck 54 ft wide.
Who owns I 315S over Int I 15?
It is owned by the State Highway Agency.