US Bridges

I 90 over RR

Fair

Gallatin County, Montana · Bozeman · Structure no. I00090309+00591

Built
1971
54 years old
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
298 ft
3 main spans
Daily traffic
10,616
2023 count
Owner
State
State Highway Agency

About this bridge

I 90 over RR is a steel continuous stringer/multi-beam or girder carrying I 90 over RR in Gallatin County, Montana. It was built in 1971, so it is 54 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 5 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 10,616 vehicles a day, roughly 12% of them trucks, projected to reach 11,465 by 2043. The structure is 298 ft (90.7 m) long and 44 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI 90
CrossesRR
LocationBozeman
RouteInterstate 90
CountyGallatin County
StateMontana
Coordinates45.67956, -111.01221
Functional classUrban 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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating27.1 US tons
Inventory rating21.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length298 ft (90.7 m)
Longest span115 ft (34.9 m)
Deck width44 ft (13.5 m)
Roadway width41 ft (12.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10,616 (2023)
Projected traffic11,465 by 2043
Trucks12%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesRailroad
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 RR built?

It was built in 1971, making it 54 years old in 2025.

What condition is I 90 over RR 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 May 2023.

How much traffic does I 90 over RR carry?

About 10,616 vehicles per day (2023 count), of which roughly 12% are trucks.

How long is I 90 over RR?

The structure is 298 ft (90.7 m) long with a longest span of 115 ft (34.9 m) and a deck 44 ft wide.

Who owns I 90 over RR?

It is owned by the State Highway Agency.