I 90 over Sep Laird St-Frontage RD
FairSilver Bow County, Montana · 3.1M W Rocker · Structure no. I00090216+06721
- Built
- 1967
- 58 years old
- Condition
- Fair
- inspected January 2024
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 158 ft
- 3 main spans
- Daily traffic
- 7,506
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
I 90 over Sep Laird St-Frontage RD is a prestressed concrete stringer/multi-beam or girder carrying I 90 over Sep Laird St-Frontage RD in Silver Bow 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 7,506 vehicles a day, roughly 15% of them trucks, projected to reach 7,881 by 2043. The structure is 158 ft (48.2 m) long and 39 ft wide. If it were closed, the detour would be 1.2 mi (2 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 | 7 Good | Some minor problems. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was I 90 over Sep Laird St-Frontage RD built?
It was built in 1967, making it 58 years old in 2025.
What condition is I 90 over Sep Laird St-Frontage RD 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 January 2024.
How much traffic does I 90 over Sep Laird St-Frontage RD carry?
About 7,506 vehicles per day (2023 count), of which roughly 15% are trucks.
How long is I 90 over Sep Laird St-Frontage RD?
The structure is 158 ft (48.2 m) long with a longest span of 56 ft (17.2 m) and a deck 39 ft wide.
Who owns I 90 over Sep Laird St-Frontage RD?
It is owned by the State Highway Agency.