US Bridges

I 90 over Sep S-271

Good

Granite County, Montana · 1.2M E Drummond · Structure no. I00090155+07871

Built
1966
59 years old
Condition
Good
inspected May 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
130 ft
3 main spans
Daily traffic
4,666
2023 count
Owner
State
State Highway Agency

About this bridge

I 90 over Sep S-271 is a prestressed concrete stringer/multi-beam or girder carrying I 90 over Sep S-271 in Granite County, Montana. It was built in 1966, so it is 59 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 4,666 vehicles a day, roughly 24% of them trucks, projected to reach 4,969 by 2043. The structure is 130 ft (39.6 m) long and 39 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesI 90
CrossesSep S-271
Location1.2M E Drummond
RouteInterstate 90
StateMontana
Coordinates46.64793, -113.1186
Functional classRural Principal Arterial - Interstate

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating53 US tons
Inventory rating35.1 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length130 ft (39.6 m)
Longest span46 ft (14 m)
Deck width39 ft (11.9 m)
Roadway width37 ft (11.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,666 (2023)
Projected traffic4,969 by 2043
Trucks24%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 90 over Sep S-271 built?

It was built in 1966, making it 59 years old in 2025.

What condition is I 90 over Sep S-271 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 May 2024.

How much traffic does I 90 over Sep S-271 carry?

About 4,666 vehicles per day (2023 count), of which roughly 24% are trucks.

How long is I 90 over Sep S-271?

The structure is 130 ft (39.6 m) long with a longest span of 46 ft (14 m) and a deck 39 ft wide.

Who owns I 90 over Sep S-271?

It is owned by the State Highway Agency.