US Bridges

STC6731;CO Line RD over Harrison Canal

Fair

Bonneville County, Idaho · 2.3 N. 5.8 E. Ucon · Structure no. 000000000020895

Built
1974
51 years old
Condition
Fair
inspected November 2024
Type
Frame
Concrete
Length
28 ft
1 main span
Daily traffic
1,700
2023 count
Owner
County
County Highway Agency

About this bridge

STC6731;CO Line RD over Harrison Canal is a concrete frame carrying STC6731;CO Line RD over Harrison Canal in Bonneville County, Idaho. It was built in 1974, so it is 51 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 1,700 vehicles a day, roughly 39% of them trucks, projected to reach 2,550 by 2042. The structure is 28 ft (8.5 m) long and 36 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesSTC6731;CO Line RD
CrossesHarrison Canal
Location2.3 N. 5.8 E. Ucon
RouteCounty Highway 6731
CountyBonneville County
StateIdaho
Coordinates43.62675, -111.84947
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating38 US tons
Inventory rating23 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 15
Structure length28 ft (8.5 m)
Longest span28 ft (8.5 m)
Deck width36 ft (11.1 m)
Roadway width34 ft (10.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,700 (2023)
Projected traffic2,550 by 2042
Trucks39%
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 STC6731;CO Line RD over Harrison Canal built?

It was built in 1974, making it 51 years old in 2025.

What condition is STC6731;CO Line RD over Harrison 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 2024.

How much traffic does STC6731;CO Line RD over Harrison Canal carry?

About 1,700 vehicles per day (2023 count), of which roughly 39% are trucks.

How long is STC6731;CO Line RD over Harrison Canal?

The structure is 28 ft (8.5 m) long with a longest span of 28 ft (8.5 m) and a deck 36 ft wide.

Who owns STC6731;CO Line RD over Harrison Canal?

It is owned by the County Highway Agency.