US Bridges

STC6731;W 145 N over Idaho Canal

Fair

Jefferson County, Idaho · 9.3 N. 0.9 W. Idaho Falls · Structure no. 000000000020880

Built
1967
58 years old
Condition
Fair
inspected November 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
71 ft
1 main span
Daily traffic
2,800
2023 count
Owner
County
County Highway Agency

About this bridge

STC6731;W 145 N over Idaho Canal is a prestressed concrete stringer/multi-beam or girder carrying STC6731;W 145 N over Idaho Canal in Jefferson 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 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 2,800 vehicles a day, roughly 7% of them trucks, projected to reach 4,200 by 2042. The structure is 71 ft (21.6 m) long and 33 ft wide. If it were closed, the detour would be 14.3 mi (23 km).

Location

Open in Google Maps
CarriesSTC6731;W 145 N
CrossesIdaho Canal
Location9.3 N. 0.9 W. Idaho Falls
RouteCounty Highway 6731
CountyJefferson County
StateIdaho
Coordinates43.62622, -112.05528
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.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating68 US tons
Inventory rating33 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 20
Structure length71 ft (21.6 m)
Longest span68 ft (20.7 m)
Deck width33 ft (10.1 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,800 (2023)
Projected traffic4,200 by 2042
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed14.3 mi (23 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$1 million (2019 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was STC6731;W 145 N over Idaho Canal built?

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

What condition is STC6731;W 145 N over Idaho 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 November 2023.

How much traffic does STC6731;W 145 N over Idaho Canal carry?

About 2,800 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is STC6731;W 145 N over Idaho Canal?

The structure is 71 ft (21.6 m) long with a longest span of 68 ft (20.7 m) and a deck 33 ft wide.

Who owns STC6731;W 145 N over Idaho Canal?

It is owned by the County Highway Agency.