US Bridges

STC3718;PRPLE Sage over Willow Creek

Fair

Canyon County, Idaho · 2.1 N. 0.9 E. Middleton · Structure no. 000000000027240

Built
1975
50 years old
Condition
Fair
inspected November 2023
Type
Tee Beam
Prestressed Concrete
Length
26 ft
1 main span
Daily traffic
2,000
2023 count
Owner
Local
Other Local Agency

About this bridge

STC3718;PRPLE Sage over Willow Creek is a prestressed concrete tee beam carrying STC3718;PRPLE Sage over Willow Creek in Canyon County, Idaho. It was built in 1975, so it is 50 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 2,000 vehicles a day, roughly 25% of them trucks, projected to reach 3,000 by 2042. The structure is 26 ft (7.9 m) long and 28 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesSTC3718;PRPLE Sage
CrossesWillow Creek
Location2.1 N. 0.9 E. Middleton
RouteCounty Highway 3718
CountyCanyon County
StateIdaho
Coordinates43.73553, -116.60297
Functional classRural Minor Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating50.6 US tons
Inventory rating36.7 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length26 ft (7.9 m)
Longest span25 ft (7.6 m)
Deck width28 ft (8.5 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,000 (2023)
Projected traffic3,000 by 2042
Trucks25%
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 STC3718;PRPLE Sage over Willow Creek built?

It was built in 1975, making it 50 years old in 2025.

What condition is STC3718;PRPLE Sage over Willow Creek 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 November 2023.

How much traffic does STC3718;PRPLE Sage over Willow Creek carry?

About 2,000 vehicles per day (2023 count), of which roughly 25% are trucks.

How long is STC3718;PRPLE Sage over Willow Creek?

The structure is 26 ft (7.9 m) long with a longest span of 25 ft (7.6 m) and a deck 28 ft wide.

Who owns STC3718;PRPLE Sage over Willow Creek?

It is owned by the Other Local Agency.