US Bridges

US 12 over RR

Fair

Fallon County, Montana · 2M SE Baker · Structure no. P00002085+07161

Built
1968
57 years old
Condition
Fair
inspected June 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
214 ft
3 main spans
Daily traffic
696
2023 count
Owner
State
State Highway Agency

About this bridge

US 12 over RR is a prestressed concrete stringer/multi-beam or girder carrying US 12 over RR in Fallon County, Montana. It was built in 1968, so it is 57 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 696 vehicles a day, roughly 10% of them trucks, projected to reach 731 by 2043. The structure is 214 ft (65.3 m) long and 35 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

CarriesUS 12
CrossesRR
Location2M SE Baker
RouteU.S. Route 12
StateMontana
Coordinates46.35397, -104.22706
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 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 geometry6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating49.1 US tons
Inventory rating23 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length214 ft (65.3 m)
Longest span72 ft (21.9 m)
Deck width35 ft (10.7 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic696 (2023)
Projected traffic731 by 2043
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesRailroad
Detour if closed123.7 mi (199 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 US 12 over RR built?

It was built in 1968, making it 57 years old in 2025.

What condition is US 12 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 June 2024.

How much traffic does US 12 over RR carry?

About 696 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is US 12 over RR?

The structure is 214 ft (65.3 m) long with a longest span of 72 ft (21.9 m) and a deck 35 ft wide.

Who owns US 12 over RR?

It is owned by the State Highway Agency.