US Bridges

Cartersville RD over Little Porcupine CR 027

Fair

Rosebud County, Montana · 8M NE Forsyth · Structure no. L44200007+02001

Built
1970
55 years old
Condition
Fair
inspected September 2024
Type
Channel Beam
Prestressed Concrete
Length
74 ft
1 main span
Daily traffic
100
2025 count
Owner
County
County Highway Agency

About this bridge

Cartersville RD over Little Porcupine CR 027 is a prestressed concrete channel beam carrying Cartersville RD over Little Porcupine CR 027 in Rosebud County, Montana. It was built in 1970, so it is 55 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 5 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 100 vehicles a day, roughly 3% of them trucks, projected to reach 100 by 2040. The structure is 74 ft (22.6 m) long and 17 ft wide. If it were closed, the detour would be 28 mi (45 km).

Location

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CarriesCartersville RD
CrossesLittle Porcupine CR 027
Location8M NE Forsyth
RouteCounty Highway 44200
CountyRosebud County
StateMontana
Coordinates46.30419, -106.57506
Functional classRural Major Collector

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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating53.9 US tons
Inventory rating32 US tons

Structure

Structure typeChannel Beam
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHS 20
Structure length74 ft (22.6 m)
Longest span73 ft (22.3 m)
Deck width17 ft (5.3 m)
Roadway width16 ft (4.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic100 (2025)
Projected traffic100 by 2040
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed28 mi (45 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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$116,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Cartersville RD over Little Porcupine CR 027 built?

It was built in 1970, making it 55 years old in 2025.

What condition is Cartersville RD over Little Porcupine CR 027 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 September 2024.

How much traffic does Cartersville RD over Little Porcupine CR 027 carry?

About 100 vehicles per day (2025 count), of which roughly 3% are trucks.

How long is Cartersville RD over Little Porcupine CR 027?

The structure is 74 ft (22.6 m) long with a longest span of 73 ft (22.3 m) and a deck 17 ft wide.

Who owns Cartersville RD over Little Porcupine CR 027?

It is owned by the County Highway Agency.