US Bridges

Underwood Road over High Line Canal

Fair

Bingham County, Idaho · 4.5N. 0.5E.ABERDEEN;2700W · Structure no. 000000000022755

Built
1970
55 years old
Condition
Fair
inspected March 2024
Type
Tee Beam
Prestressed Concrete
Length
42 ft
1 main span
Daily traffic
120
2023 count
Owner
County
County Highway Agency

About this bridge

Underwood Road over High Line Canal is a prestressed concrete tee beam carrying Underwood Road over High Line Canal in Bingham County, Idaho. It was built in 1970, so it is 55 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.

It carries about 120 vehicles a day, roughly 10% of them trucks, projected to reach 180 by 2039. The structure is 42 ft (12.8 m) long and 30 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesUnderwood Road
CrossesHigh Line Canal
Location4.5N. 0.5E.ABERDEEN;2700W
RouteCounty Highway 0
CountyBingham County
StateIdaho
Coordinates43.00928, -112.82856
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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating30 US tons
Inventory rating18 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length42 ft (12.8 m)
Longest span41 ft (12.5 m)
Deck width30 ft (9.1 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic120 (2023)
Projected traffic180 by 2039
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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$450,000 (2020 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Underwood Road over High Line Canal built?

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

What condition is Underwood Road over High Line 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 March 2024.

How much traffic does Underwood Road over High Line Canal carry?

About 120 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is Underwood Road over High Line Canal?

The structure is 42 ft (12.8 m) long with a longest span of 41 ft (12.5 m) and a deck 30 ft wide.

Who owns Underwood Road over High Line Canal?

It is owned by the County Highway Agency.