US Bridges

55th East Road over Anderson Canal

Fair

Bonneville County, Idaho · 4.5 N. Iona · Structure no. 000000000031370

Built
1954
71 years old, rebuilt 1971
Condition
Fair
inspected November 2024
Type
Frame
Concrete
Length
24 ft
1 main span
Daily traffic
1,300
2023 count
Owner
County
County Highway Agency

About this bridge

55th East Road over Anderson Canal is a concrete frame carrying 55th East Road over Anderson Canal in Bonneville County, Idaho. It was built in 1954 and reconstructed in 1971, so it is 71 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 1,300 vehicles a day, roughly 24% of them trucks, projected to reach 1,950 by 2042. The structure is 24 ft (7.3 m) long and 38 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
Carries55th East Road
CrossesAnderson Canal
Location4.5 N. Iona
RouteCounty Highway 0
CountyBonneville County
StateIdaho
Coordinates43.59175, -111.92386
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 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 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 rating57 US tons
Inventory rating34 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 15
Structure length24 ft (7.3 m)
Longest span24 ft (7.3 m)
Deck width38 ft (11.7 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,300 (2023)
Projected traffic1,950 by 2042
Trucks24%
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 55th East Road over Anderson Canal built?

It was built in 1954, making it 71 years old in 2025. It was reconstructed in 1971.

What condition is 55th East Road over Anderson 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 55th East Road over Anderson Canal carry?

About 1,300 vehicles per day (2023 count), of which roughly 24% are trucks.

How long is 55th East Road over Anderson Canal?

The structure is 24 ft (7.3 m) long with a longest span of 24 ft (7.3 m) and a deck 38 ft wide.

Who owns 55th East Road over Anderson Canal?

It is owned by the County Highway Agency.