US Bridges

S. Firth Road over Reservation Canal

FairPosted for load

Bingham County, Idaho · 0.6 S. 0.3 E. Firth · Structure no. 000000000022455

Built
1967
58 years old
Condition
Fair
inspected April 2023
Type
Tee Beam
Prestressed Concrete
Length
46 ft
1 main span
Daily traffic
220
2023 count
Owner
County
County Highway Agency

About this bridge

S. Firth Road over Reservation Canal is a prestressed concrete tee beam carrying S. Firth Road over Reservation Canal in Bingham County, Idaho. It was built in 1967, so it is 58 years old, older than the Idaho average of 45.3 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. Its operating status is: posted for load restriction.

It carries about 220 vehicles a day, roughly 50% of them trucks, projected to reach 330 by 2042. The structure is 46 ft (14 m) long and 28 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

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CarriesS. Firth Road
CrossesReservation Canal
Location0.6 S. 0.3 E. Firth
RouteCounty Highway 0
CountyBingham County
StateIdaho
Coordinates43.29453, -112.17831
Functional classRural Minor 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
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating30 US tons
Inventory rating18 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length46 ft (14 m)
Longest span45 ft (13.7 m)
Deck width28 ft (8.5 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic220 (2023)
Projected traffic330 by 2042
Trucks50%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$513,000 (2021 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was S. Firth Road over Reservation Canal built?

It was built in 1967, making it 58 years old in 2025.

What condition is S. Firth Road over Reservation Canal 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 April 2023.

How much traffic does S. Firth Road over Reservation Canal carry?

About 220 vehicles per day (2023 count), of which roughly 50% are trucks.

How long is S. Firth Road over Reservation Canal?

The structure is 46 ft (14 m) long with a longest span of 45 ft (13.7 m) and a deck 28 ft wide.

Who owns S. Firth Road over Reservation Canal?

It is owned by the County Highway Agency.