US Bridges

US 20B;BRIDGE ST over US 20;ST. Anthony Ic

Good

Fremont County, Idaho · In ST Anthony · Structure no. 000000000012725

Built
1984
41 years old
Condition
Good
inspected May 2022
Type
Box Beam or Girders - Single or Spread
Prestressed Concrete Continuous
Length
218 ft
2 main spans
Daily traffic
8,300
2023 count
Owner
State
State Highway Agency

About this bridge

US 20B;BRIDGE ST over US 20;ST. Anthony Ic is a prestressed concrete continuous box beam or girders - single or spread carrying US 20B;BRIDGE ST over US 20;ST. Anthony Ic in Fremont County, Idaho. It was built in 1984, so it is 41 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 8,300 vehicles a day, roughly 8% of them trucks, projected to reach 12,450 by 2042. The structure is 218 ft (66.4 m) long and 87 ft wide.

Location

Open in Google Maps
CarriesUS 20B;BRIDGE ST
CrossesUS 20;ST. Anthony Ic
LocationIn ST Anthony
RouteU.S. Route 20
CountyFremont County
StateIdaho
Coordinates43.96242, -111.68206
Functional classRural Major Collector

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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionMay 2022
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating84 US tons
Inventory rating23 US tons

Structure

Structure typeBox Beam or Girders - Single or Spread
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 25 or greater
Structure length218 ft (66.4 m)
Longest span108 ft (32.9 m)
Deck width87 ft (26.4 m)
Roadway width72 ft (21.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,300 (2023)
Projected traffic12,450 by 2042
Trucks8%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed—
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$9.3 million (2020 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was US 20B;BRIDGE ST over US 20;ST. Anthony Ic built?

It was built in 1984, making it 41 years old in 2025.

What condition is US 20B;BRIDGE ST over US 20;ST. Anthony Ic 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 May 2022.

How much traffic does US 20B;BRIDGE ST over US 20;ST. Anthony Ic carry?

About 8,300 vehicles per day (2023 count), of which roughly 8% are trucks.

How long is US 20B;BRIDGE ST over US 20;ST. Anthony Ic?

The structure is 218 ft (66.4 m) long with a longest span of 108 ft (32.9 m) and a deck 87 ft wide.

Who owns US 20B;BRIDGE ST over US 20;ST. Anthony Ic?

It is owned by the State Highway Agency.