US Bridges

I 115S over Excelsior Ave

Fair

Silver Bow County, Montana · Butte · Structure no. I00115001+01872

Built
1955
70 years old
Condition
Fair
inspected May 2023
Type
Tee Beam
Concrete Continuous
Length
156 ft
3 main spans
Daily traffic
2,242
2023 count
Owner
State
State Highway Agency

About this bridge

I 115S over Excelsior Ave is a concrete continuous tee beam carrying I 115S over Excelsior Ave in Silver Bow County, Montana. It was built in 1955, so it is 70 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 2,242 vehicles a day, roughly 1% of them trucks, projected to reach 2,354 by 2043. The structure is 156 ft (47.5 m) long and 36 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI 115S
CrossesExcelsior Ave
LocationButte
RouteInterstate 115
CountySilver Bow County
StateMontana
Coordinates46.00357, -112.55013
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment8: Equal to present desirable criteria
Operating rating38 US tons
Inventory rating29 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHL 93
Structure length156 ft (47.5 m)
Longest span60 ft (18.3 m)
Deck width36 ft (10.9 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,242 (2023)
Projected traffic2,354 by 2043
Trucks1%
Lanes on structure2
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
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$498,000
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 115S over Excelsior Ave built?

It was built in 1955, making it 70 years old in 2025.

What condition is I 115S over Excelsior Ave 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 115S over Excelsior Ave carry?

About 2,242 vehicles per day (2023 count), of which roughly 1% are trucks.

How long is I 115S over Excelsior Ave?

The structure is 156 ft (47.5 m) long with a longest span of 60 ft (18.3 m) and a deck 36 ft wide.

Who owns I 115S over Excelsior Ave?

It is owned by the State Highway Agency.