US Bridges

I 90 over RR

Fair

Missoula County, Montana · 0.6M W Bonner · Structure no. I00090110+00332

Built
1963
62 years old, rebuilt 1994
Condition
Fair
inspected May 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
359 ft
3 main spans
Daily traffic
6,216
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 Missoula County, Montana. It was built in 1963 and reconstructed in 1994, so it is 62 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 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 6,216 vehicles a day, roughly 19% of them trucks, projected to reach 6,526 by 2043. The structure is 359 ft (109.4 m) long and 41 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI 90
CrossesRR
Location0.6M W Bonner
RouteInterstate 90
CountyMissoula County
StateMontana
Coordinates46.87354, -113.88899
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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Last inspectionMay 2024
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 geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating29 US tons
Inventory rating22 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3 (+3 approach)
Design loadHS 20
Structure length359 ft (109.4 m)
Longest span69 ft (21 m)
Deck width41 ft (12.5 m)
Roadway width38 ft (11.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,216 (2023)
Projected traffic6,526 by 2043
Trucks19%
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 1963, making it 62 years old in 2025. It was reconstructed in 1994.

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 2024.

How much traffic does I 90 over RR carry?

About 6,216 vehicles per day (2023 count), of which roughly 19% are trucks.

How long is I 90 over RR?

The structure is 359 ft (109.4 m) long with a longest span of 69 ft (21 m) and a deck 41 ft wide.

Who owns I 90 over RR?

It is owned by the State Highway Agency.