US Bridges

N 4300 E RD over Dry Bed Canal

Fair

Jefferson County, Idaho · 0.9 N. 3.5 E. Rigby · Structure no. 000000000032555

Built
1974
51 years old
Condition
Fair
inspected March 2024
Type
Tee Beam
Prestressed Concrete
Length
30 ft
1 main span
Daily traffic
20
2023 count
Owner
County
County Highway Agency

About this bridge

N 4300 E RD over Dry Bed Canal is a prestressed concrete tee beam carrying N 4300 E RD over Dry Bed Canal in Jefferson 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 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 20 vehicles a day, roughly 10% of them trucks, projected to reach 30 by 2039. The structure is 30 ft (9.1 m) long and 16 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

CarriesN 4300 E RD
CrossesDry Bed Canal
Location0.9 N. 3.5 E. Rigby
RouteCounty Highway 0
StateIdaho
Coordinates43.68156, -111.84419
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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating36.7 US tons
Inventory rating26.8 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 15
Structure length30 ft (9.1 m)
Longest span29 ft (8.8 m)
Deck width16 ft (4.9 m)
Roadway width14 ft (4.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic20 (2023)
Projected traffic30 by 2039
Trucks10%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 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$354,000 (2020 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was N 4300 E RD over Dry Bed Canal built?

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

What condition is N 4300 E RD over Dry Bed 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 N 4300 E RD over Dry Bed Canal carry?

About 20 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is N 4300 E RD over Dry Bed Canal?

The structure is 30 ft (9.1 m) long with a longest span of 29 ft (8.8 m) and a deck 16 ft wide.

Who owns N 4300 E RD over Dry Bed Canal?

It is owned by the County Highway Agency.