US Bridges

N 3980 East Road over Dry Bed

Good

Jefferson County, Idaho · 1.8 N. 0.3 E. Rigby · Structure no. 000000000036105

Built
1992
33 years old
Condition
Good
inspected November 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
51 ft
1 main span
Daily traffic
100
2023 count
Owner
County
County Highway Agency

About this bridge

N 3980 East Road over Dry Bed is a steel stringer/multi-beam or girder carrying N 3980 East Road over Dry Bed in Jefferson County, Idaho. It was built in 1992, so it is 33 years old, younger than the Idaho average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 100 vehicles a day, roughly 5% of them trucks, projected to reach 150 by 2039. The structure is 51 ft (15.5 m) long and 33 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesN 3980 East Road
CrossesDry Bed
Location1.8 N. 0.3 E. Rigby
RouteCounty Highway 0
StateIdaho
Coordinates43.69875, -111.90836
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating47 US tons
Inventory rating28 US tons

Structure

MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length51 ft (15.5 m)
Longest span50 ft (15.2 m)
Deck width33 ft (10.1 m)
Roadway width30 ft (9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic100 (2023)
Projected traffic150 by 2039
Trucks5%
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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was N 3980 East Road over Dry Bed built?

It was built in 1992, making it 33 years old in 2025.

What condition is N 3980 East Road over Dry Bed in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in November 2024.

How much traffic does N 3980 East Road over Dry Bed carry?

About 100 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is N 3980 East Road over Dry Bed?

The structure is 51 ft (15.5 m) long with a longest span of 50 ft (15.2 m) and a deck 33 ft wide.

Who owns N 3980 East Road over Dry Bed?

It is owned by the County Highway Agency.