US Bridges

I 90 over RR

Fair

Mineral County, Montana · 9.3M W Alberton · Structure no. I00090066+04212

Built
1965
60 years old
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
339 ft
2 main spans
Daily traffic
4,088
2023 count
Owner
State
State Highway Agency

About this bridge

I 90 over RR is a steel stringer/multi-beam or girder carrying I 90 over RR in Mineral County, Montana. It was built in 1965, so it is 60 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 4,088 vehicles a day, roughly 23% of them trucks, projected to reach 4,292 by 2043. The structure is 339 ft (103.3 m) long and 32 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI 90
CrossesRR
Location9.3M W Alberton
RouteInterstate 90
CountyMineral County
StateMontana
Coordinates47.01914, -114.65492
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
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Approach roadway alignment8: Equal to present desirable criteria
Operating rating50 US tons
Inventory rating36 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans2 (+5 approach)
Design loadHS 20
Structure length339 ft (103.3 m)
Longest span51 ft (15.5 m)
Deck width32 ft (9.7 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,088 (2023)
Projected traffic4,292 by 2043
Trucks23%
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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$962,000
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 90 over RR built?

It was built in 1965, making it 60 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 4,088 vehicles per day (2023 count), of which roughly 23% are trucks.

How long is I 90 over RR?

The structure is 339 ft (103.3 m) long with a longest span of 51 ft (15.5 m) and a deck 32 ft wide.

Who owns I 90 over RR?

It is owned by the State Highway Agency.