US Bridges

US 20 Wbl over N.Fk.Teton River

Fair

Madison County, Idaho · 2.0 N. Sugar City · Structure no. 000000000012585

Built
1979
46 years old
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
101 ft
1 main span
Daily traffic
7,750
2023 count
Owner
State
State Highway Agency

About this bridge

US 20 Wbl over N.Fk.Teton River is a prestressed concrete stringer/multi-beam or girder carrying US 20 Wbl over N.Fk.Teton River in Madison County, Idaho. It was built in 1979, so it is 46 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 7,750 vehicles a day, roughly 11% of them trucks, projected to reach 11,625 by 2042. The structure is 101 ft (30.8 m) long and 44 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesUS 20 Wbl
CrossesN.Fk.Teton River
Location2.0 N. Sugar City
RouteU.S. Route 20
CountyMadison County
StateIdaho
Coordinates43.88969, -111.74414
Functional classRural Principal Arterial - Other

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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 2023
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 adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating66 US tons
Inventory rating33 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length101 ft (30.8 m)
Longest span99 ft (30.2 m)
Deck width44 ft (13.3 m)
Roadway width41 ft (12.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,750 (2023)
Projected traffic11,625 by 2042
Trucks11%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 US 20 Wbl over N.Fk.Teton River built?

It was built in 1979, making it 46 years old in 2025.

What condition is US 20 Wbl over N.Fk.Teton River 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 July 2023.

How much traffic does US 20 Wbl over N.Fk.Teton River carry?

About 7,750 vehicles per day (2023 count), of which roughly 11% are trucks.

How long is US 20 Wbl over N.Fk.Teton River?

The structure is 101 ft (30.8 m) long with a longest span of 99 ft (30.2 m) and a deck 44 ft wide.

Who owns US 20 Wbl over N.Fk.Teton River?

It is owned by the State Highway Agency.