US Bridges

S 80 over RR

Fair

Chouteau County, Montana · 1M NW Fort Benton · Structure no. P00080000+02091

Built
1953
72 years old
Condition
Fair
inspected March 2023
Type
Tee Beam
Concrete
Length
130 ft
3 main spans
Daily traffic
849
2023 count
Owner
State
State Highway Agency

About this bridge

S 80 over RR is a concrete tee beam carrying S 80 over RR in Chouteau County, Montana. It was built in 1953, so it is 72 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 849 vehicles a day, roughly 9% of them trucks, projected to reach 891 by 2043. The structure is 130 ft (39.6 m) long and 27 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesS 80
CrossesRR
Location1M NW Fort Benton
RouteState Highway 80
CountyChouteau County
StateMontana
Coordinates47.83607, -110.68513
Functional classRural Minor Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 2023
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 geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating31 US tons
Inventory rating21.1 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 15
Structure length130 ft (39.6 m)
Longest span47 ft (14.2 m)
Deck width27 ft (8.1 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic849 (2023)
Projected traffic891 by 2043
Trucks9%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesRailroad
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

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 S 80 over RR built?

It was built in 1953, making it 72 years old in 2025.

What condition is S 80 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 March 2023.

How much traffic does S 80 over RR carry?

About 849 vehicles per day (2023 count), of which roughly 9% are trucks.

How long is S 80 over RR?

The structure is 130 ft (39.6 m) long with a longest span of 47 ft (14.2 m) and a deck 27 ft wide.

Who owns S 80 over RR?

It is owned by the State Highway Agency.