US Bridges

I 90 over Bbwa Canal

Fair

Yellowstone County, Montana · 3.7M E Laurel · Structure no. I00090438+00391

Built
1964
61 years old
Condition
Fair
inspected October 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
41 ft
1 main span
Daily traffic
12,397
2023 count
Owner
State
State Highway Agency

About this bridge

I 90 over Bbwa Canal is a prestressed concrete stringer/multi-beam or girder carrying I 90 over Bbwa Canal in Yellowstone County, Montana. It was built in 1964, so it is 61 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 12,397 vehicles a day, roughly 10% of them trucks, projected to reach 13,016 by 2043. The structure is 41 ft (12.5 m) long and 41 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesI 90
CrossesBbwa Canal
Location3.7M E Laurel
RouteInterstate 90
StateMontana
Coordinates45.68684, -108.6959
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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating56 US tons
Inventory rating42 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length41 ft (12.5 m)
Longest span40 ft (12.2 m)
Deck width41 ft (12.6 m)
Roadway width38 ft (11.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic12,397 (2023)
Projected traffic13,016 by 2043
Trucks10%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
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—
NavigationNo navigation control on waterway

Frequently asked questions

When was I 90 over Bbwa Canal built?

It was built in 1964, making it 61 years old in 2025.

What condition is I 90 over Bbwa Canal 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 October 2023.

How much traffic does I 90 over Bbwa Canal carry?

About 12,397 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is I 90 over Bbwa Canal?

The structure is 41 ft (12.5 m) long with a longest span of 40 ft (12.2 m) and a deck 41 ft wide.

Who owns I 90 over Bbwa Canal?

It is owned by the State Highway Agency.