US Bridges

I 90 over Sep Milwaukee Avenue

Fair

Powell County, Montana · Deer Lodge · Structure no. I00090185+10121

Built
1961
64 years old
Condition
Fair
inspected December 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
118 ft
3 main spans
Daily traffic
4,371
2023 count
Owner
State
State Highway Agency

About this bridge

I 90 over Sep Milwaukee Avenue is a prestressed concrete stringer/multi-beam or girder carrying I 90 over Sep Milwaukee Avenue in Powell County, Montana. It was built in 1961, so it is 64 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 4,371 vehicles a day, roughly 24% of them trucks, projected to reach 4,720 by 2043. The structure is 118 ft (36 m) long and 47 ft wide.

Location

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CarriesI 90
CrossesSep Milwaukee Avenue
LocationDeer Lodge
RouteInterstate 90
CountyPowell County
StateMontana
Coordinates46.39735, -112.7176
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Last inspectionDecember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46 US tons
Inventory rating36 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length118 ft (36 m)
Longest span46 ft (14 m)
Deck width47 ft (14.3 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,371 (2023)
Projected traffic4,720 by 2043
Trucks24%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed—
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 Sep Milwaukee Avenue built?

It was built in 1961, making it 64 years old in 2025.

What condition is I 90 over Sep Milwaukee Avenue 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 December 2023.

How much traffic does I 90 over Sep Milwaukee Avenue carry?

About 4,371 vehicles per day (2023 count), of which roughly 24% are trucks.

How long is I 90 over Sep Milwaukee Avenue?

The structure is 118 ft (36 m) long with a longest span of 46 ft (14 m) and a deck 47 ft wide.

Who owns I 90 over Sep Milwaukee Avenue?

It is owned by the State Highway Agency.