US Bridges

Highline Road over Blackfoot Canal

Fair

Bingham County, Idaho · 0.4 S. 0.2 W. Firth · Structure no. 000000000023025

Built
1971
54 years old
Condition
Fair
inspected April 2023
Type
Tee Beam
Prestressed Concrete
Length
36 ft
1 main span
Daily traffic
400
2023 count
Owner
County
County Highway Agency

About this bridge

Highline Road over Blackfoot Canal is a prestressed concrete tee beam carrying Highline Road over Blackfoot Canal in Bingham County, Idaho. It was built in 1971, so it is 54 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 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 400 vehicles a day, roughly 10% of them trucks, projected to reach 600 by 2039. The structure is 36 ft (11 m) long and 30 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesHighline Road
CrossesBlackfoot Canal
Location0.4 S. 0.2 W. Firth
RouteCounty Highway 0
CountyBingham County
StateIdaho
Coordinates43.29706, -112.18503
Functional classRural Local

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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2023
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating66 US tons
Inventory rating39.7 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length36 ft (11 m)
Longest span34 ft (10.4 m)
Deck width30 ft (9.1 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic400 (2023)
Projected traffic600 by 2039
Trucks10%
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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Highline Road over Blackfoot Canal built?

It was built in 1971, making it 54 years old in 2025.

What condition is Highline Road over Blackfoot 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 Highline Road over Blackfoot Canal carry?

About 400 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is Highline Road over Blackfoot Canal?

The structure is 36 ft (11 m) long with a longest span of 34 ft (10.4 m) and a deck 30 ft wide.

Who owns Highline Road over Blackfoot Canal?

It is owned by the County Highway Agency.