US Bridges

STC7456; E Iona RD over Sand Creek

Fair

Bonneville County, Idaho · 2.0 W. Iona · Structure no. 000000000020830

Built
1957
68 years old
Condition
Fair
inspected November 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
70 ft
3 main spans
Daily traffic
4,300
2023 count
Owner
County
County Highway Agency

About this bridge

STC7456; E Iona RD over Sand Creek is a prestressed concrete box beam or girders - multiple carrying STC7456; E Iona RD over Sand Creek in Bonneville County, Idaho. It was built in 1957, so it is 68 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 4,300 vehicles a day, roughly 19% of them trucks, projected to reach 6,450 by 2042. The structure is 70 ft (21.3 m) long and 30 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesSTC7456; E Iona RD
CrossesSand Creek
Location2.0 W. Iona
RouteCounty Highway 7456
CountyBonneville County
StateIdaho
Coordinates43.52572, -111.96164
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.
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 protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating30 US tons
Inventory rating18 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadH 15
Structure length70 ft (21.3 m)
Longest span30 ft (9.1 m)
Deck width30 ft (9.2 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,300 (2023)
Projected traffic6,450 by 2042
Trucks19%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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 (2017 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was STC7456; E Iona RD over Sand Creek built?

It was built in 1957, making it 68 years old in 2025.

What condition is STC7456; E Iona RD over Sand Creek 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 STC7456; E Iona RD over Sand Creek carry?

About 4,300 vehicles per day (2023 count), of which roughly 19% are trucks.

How long is STC7456; E Iona RD over Sand Creek?

The structure is 70 ft (21.3 m) long with a longest span of 30 ft (9.1 m) and a deck 30 ft wide.

Who owns STC7456; E Iona RD over Sand Creek?

It is owned by the County Highway Agency.