US Bridges

IRR - I 90 over Sep Local Road

Fair

Big Horn County, Montana · 8.7M S Lodge Grass · Structure no. I00090539+05881

Built
1985
40 years old
Condition
Fair
inspected January 2024
Type
Slab
Concrete Continuous
Length
81 ft
3 main spans
Daily traffic
2,013
2023 count
Owner
State
State Highway Agency

About this bridge

IRR - I 90 over Sep Local Road is a concrete continuous slab carrying IRR - I 90 over Sep Local Road in Big Horn County, Montana. It was built in 1985, so it is 40 years old, younger 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 2,013 vehicles a day, roughly 24% of them trucks, projected to reach 2,153 by 2043. The structure is 81 ft (24.7 m) long and 40 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesIRR - I 90
CrossesSep Local Road
Location8.7M S Lodge Grass
RouteInterstate 90
CountyBig Horn County
StateMontana
Coordinates45.19102, -107.3641
Functional classRural Principal Arterial - Interstate

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJanuary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to 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 rating43 US tons
Inventory rating33 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length81 ft (24.7 m)
Longest span30 ft (9.1 m)
Deck width40 ft (12.3 m)
Roadway width37 ft (11.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,013 (2023)
Projected traffic2,153 by 2043
Trucks24%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesOther
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 IRR - I 90 over Sep Local Road built?

It was built in 1985, making it 40 years old in 2025.

What condition is IRR - I 90 over Sep Local Road 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 IRR - I 90 over Sep Local Road carry?

About 2,013 vehicles per day (2023 count), of which roughly 24% are trucks.

How long is IRR - I 90 over Sep Local Road?

The structure is 81 ft (24.7 m) long with a longest span of 30 ft (9.1 m) and a deck 40 ft wide.

Who owns IRR - I 90 over Sep Local Road?

It is owned by the State Highway Agency.