US Bridges

SH 28 over Agency Creek

Good

Lemhi County, Idaho · 0.1 S. Tendoy · Structure no. 000000000013419

Built
2019
6 years old
Condition
Good
inspected August 2022
Type
Frame
Concrete
Length
24 ft
1 main span
Daily traffic
860
2023 count
Owner
State
State Highway Agency

About this bridge

SH 28 over Agency Creek is a concrete frame carrying SH 28 over Agency Creek in Lemhi County, Idaho. It was built in 2019, so it is 6 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 860 vehicles a day, roughly 25% of them trucks, projected to reach 1,290 by 2042. The structure is 24 ft (7.3 m) long and 45 ft wide. If it were closed, the detour would be 78.3 mi (126 km).

Location

Open in Google Maps
CarriesSH 28
CrossesAgency Creek
Location0.1 S. Tendoy
RouteState Highway 28
CountyLemhi County
StateIdaho
Coordinates44.95911, -113.64422
Functional classRural Minor Arterial

Condition and inspection

Good

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

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection9 ExcellentNo problems noted.
Last inspectionAugust 2022
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating75 US tons
Inventory rating57.9 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, precast panels
Main spans1
Design loadHL 93
Structure length24 ft (7.3 m)
Longest span23 ft (6.9 m)
Deck width45 ft (13.7 m)
Roadway width42 ft (12.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic860 (2023)
Projected traffic1,290 by 2042
Trucks25%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed78.3 mi (126 km)
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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was SH 28 over Agency Creek built?

It was built in 2019, making it 6 years old in 2025.

What condition is SH 28 over Agency Creek 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 August 2022.

How much traffic does SH 28 over Agency Creek carry?

About 860 vehicles per day (2023 count), of which roughly 25% are trucks.

How long is SH 28 over Agency Creek?

The structure is 24 ft (7.3 m) long with a longest span of 23 ft (6.9 m) and a deck 45 ft wide.

Who owns SH 28 over Agency Creek?

It is owned by the State Highway Agency.