US Bridges

N 3600 E over Combined Snake Rivers

Fair

Madison County, Idaho · 5.1 S. 9.6 W. Rexburg · Structure no. 000000000032785

Built
1968
57 years old
Condition
Fair
inspected October 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
340 ft
3 main spans
Daily traffic
270
2023 count
Owner
County
County Highway Agency

About this bridge

N 3600 E over Combined Snake Rivers is a prestressed concrete stringer/multi-beam or girder carrying N 3600 E over Combined Snake Rivers in Madison County, Idaho. It was built in 1968, so it is 57 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 270 vehicles a day, roughly 10% of them trucks, projected to reach 405 by 2039. The structure is 340 ft (103.6 m) long and 30 ft wide. If it were closed, the detour would be 11.8 mi (19 km).

Location

Open in Google Maps
CarriesN 3600 E
CrossesCombined Snake Rivers
Location5.1 S. 9.6 W. Rexburg
RouteCounty Highway 0
CountyMadison County
StateIdaho
Coordinates43.75206, -111.98031
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
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 alignment7: Better than present minimum criteria
Operating rating30 US tons
Inventory rating18 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length340 ft (103.6 m)
Longest span105 ft (32 m)
Deck width30 ft (9.1 m)
Roadway width26 ft (8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic270 (2023)
Projected traffic405 by 2039
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.8 mi (19 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$2.8 million (2020 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was N 3600 E over Combined Snake Rivers built?

It was built in 1968, making it 57 years old in 2025.

What condition is N 3600 E over Combined Snake Rivers 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 October 2024.

How much traffic does N 3600 E over Combined Snake Rivers carry?

About 270 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is N 3600 E over Combined Snake Rivers?

The structure is 340 ft (103.6 m) long with a longest span of 105 ft (32 m) and a deck 30 ft wide.

Who owns N 3600 E over Combined Snake Rivers?

It is owned by the County Highway Agency.