I 15 over Sep Sierra RD E
GoodLewis and Clark County, Montana · 4M N Helena · Structure no. I00015197+00392
- Built
- 1962
- 63 years old
- Condition
- Good
- inspected September 2023
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 120 ft
- 3 main spans
- Daily traffic
- 6,202
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
I 15 over Sep Sierra RD E is a prestressed concrete stringer/multi-beam or girder carrying I 15 over Sep Sierra RD E in Lewis and Clark County, Montana. It was built in 1962, so it is 63 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 6,202 vehicles a day, roughly 9% of them trucks, projected to reach 6,729 by 2043. The structure is 120 ft (36.7 m) long and 41 ft wide. If it were closed, the detour would be 1.2 mi (2 km).
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 I 15 over Sep Sierra RD E built?
It was built in 1962, making it 63 years old in 2025.
What condition is I 15 over Sep Sierra RD E 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 September 2023.
How much traffic does I 15 over Sep Sierra RD E carry?
About 6,202 vehicles per day (2023 count), of which roughly 9% are trucks.
How long is I 15 over Sep Sierra RD E?
The structure is 120 ft (36.7 m) long with a longest span of 47 ft (14.2 m) and a deck 41 ft wide.
Who owns I 15 over Sep Sierra RD E?
It is owned by the State Highway Agency.