US Bridges

I 90 over RR

Fair

Jefferson County, Montana · 5.6M W Whitehall · Structure no. I00090243+03221

Built
1966
59 years old
Condition
Fair
inspected September 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
316 ft
3 main spans
Daily traffic
4,650
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 Jefferson County, Montana. It was built in 1966, so it is 59 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 4,650 vehicles a day, roughly 24% of them trucks, projected to reach 4,952 by 2043. The structure is 316 ft (96.3 m) long and 32 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI 90
CrossesRR
Location5.6M W Whitehall
RouteInterstate 90
CountyJefferson County
StateMontana
Coordinates45.90078, -112.21545
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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 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 geometry3: Basically intolerable, requiring high priority of corrective action
Approach roadway alignment8: Equal to present desirable criteria
Operating rating28 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 length316 ft (96.3 m)
Longest span65 ft (19.7 m)
Deck width32 ft (9.9 m)
Roadway width29 ft (8.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,650 (2023)
Projected traffic4,952 by 2043
Trucks24%
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$917,000
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 90 over RR built?

It was built in 1966, making it 59 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 September 2024.

How much traffic does I 90 over RR carry?

About 4,650 vehicles per day (2023 count), of which roughly 24% are trucks.

How long is I 90 over RR?

The structure is 316 ft (96.3 m) long with a longest span of 65 ft (19.7 m) and a deck 32 ft wide.

Who owns I 90 over RR?

It is owned by the State Highway Agency.