US Bridges

STC3821;OLD HWY 30 over Alkali Creek

Good

Elmore County, Idaho · 3.0 W. Glenns Ferry · Structure no. 000000000027925

Built
1977
48 years old
Condition
Good
inspected March 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
40 ft
1 main span
Daily traffic
1,000
2023 count
Owner
Local
Other Local Agency

About this bridge

STC3821;OLD HWY 30 over Alkali Creek is a prestressed concrete stringer/multi-beam or girder carrying STC3821;OLD HWY 30 over Alkali Creek in Elmore County, Idaho. It was built in 1977, so it is 48 years old, older 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 1,000 vehicles a day, projected to reach 1,500 by 2042. The structure is 40 ft (12.2 m) long and 32 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesSTC3821;OLD HWY 30
CrossesAlkali Creek
Location3.0 W. Glenns Ferry
RouteCounty Highway 3821
CountyElmore County
StateIdaho
Coordinates42.95694, -115.36456
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.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating51 US tons
Inventory rating28 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length40 ft (12.2 m)
Longest span38 ft (11.6 m)
Deck width32 ft (9.7 m)
Roadway width29 ft (8.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,000 (2023)
Projected traffic1,500 by 2042
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerOther Local Agency
Maintained byOther Local 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 STC3821;OLD HWY 30 over Alkali Creek built?

It was built in 1977, making it 48 years old in 2025.

What condition is STC3821;OLD HWY 30 over Alkali 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 March 2023.

How much traffic does STC3821;OLD HWY 30 over Alkali Creek carry?

About 1,000 vehicles per day (2023 count).

How long is STC3821;OLD HWY 30 over Alkali Creek?

The structure is 40 ft (12.2 m) long with a longest span of 38 ft (11.6 m) and a deck 32 ft wide.

Who owns STC3821;OLD HWY 30 over Alkali Creek?

It is owned by the Other Local Agency.