US Bridges

I 90 Frontage RD over Bighorn River

Fair

Big Horn County, Montana · 1M E Hardin · Structure no. S00384000+05101

Built
2007
18 years old
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
591 ft
3 main spans
Daily traffic
1,455
2023 count
Owner
State
State Highway Agency

About this bridge

I 90 Frontage RD over Bighorn River is a steel continuous stringer/multi-beam or girder carrying I 90 Frontage RD over Bighorn River in Big Horn County, Montana. It was built in 2007, so it is 18 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 1,455 vehicles a day, roughly 2% of them trucks, projected to reach 1,528 by 2043. The structure is 591 ft (180 m) long and 34 ft wide. If it were closed, the detour would be 29.8 mi (48 km).

Location

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CarriesI 90 Frontage RD
CrossesBighorn River
Location1M E Hardin
RouteState Highway 384
CountyBig Horn County
StateMontana
Coordinates45.73676, -107.57428
Functional classRural Major Collector

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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating72 US tons
Inventory rating56 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3 (+2 approach)
Design loadHL 93
Structure length591 ft (180 m)
Longest span197 ft (60 m)
Deck width34 ft (10.3 m)
Roadway width31 ft (9.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,455 (2023)
Projected traffic1,528 by 2043
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed29.8 mi (48 km)
TollOn a free road
National Highway SystemNo

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$1.1 million
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was I 90 Frontage RD over Bighorn River built?

It was built in 2007, making it 18 years old in 2025.

What condition is I 90 Frontage RD over Bighorn River 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 April 2023.

How much traffic does I 90 Frontage RD over Bighorn River carry?

About 1,455 vehicles per day (2023 count), of which roughly 2% are trucks.

How long is I 90 Frontage RD over Bighorn River?

The structure is 591 ft (180 m) long with a longest span of 197 ft (60 m) and a deck 34 ft wide.

Who owns I 90 Frontage RD over Bighorn River?

It is owned by the State Highway Agency.