S 518 over Int Montana City-I 15
GoodJefferson County, Montana · Montana City · Structure no. S00518000+00001
- Built
- 1968
- 57 years old
- Condition
- Good
- inspected March 2024
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 297 ft
- 4 main spans
- Daily traffic
- 5,885
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
S 518 over Int Montana City-I 15 is a prestressed concrete stringer/multi-beam or girder carrying S 518 over Int Montana City-I 15 in Jefferson County, Montana. It was built in 1968, so it is 57 years old, older than the Montana average of 47 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 5,885 vehicles a day, roughly 1% of them trucks, projected to reach 6,297 by 2043. The structure is 297 ft (90.5 m) long and 34 ft wide.
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 |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| 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 S 518 over Int Montana City-I 15 built?
It was built in 1968, making it 57 years old in 2025.
What condition is S 518 over Int Montana City-I 15 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 March 2024.
How much traffic does S 518 over Int Montana City-I 15 carry?
About 5,885 vehicles per day (2023 count), of which roughly 1% are trucks.
How long is S 518 over Int Montana City-I 15?
The structure is 297 ft (90.5 m) long with a longest span of 75 ft (22.9 m) and a deck 34 ft wide.
Who owns S 518 over Int Montana City-I 15?
It is owned by the State Highway Agency.