US Bridges

Nipper Road over Downy Marsh Valley Cnl

Fair

Caribou County, Idaho · 5.6 N. 3.1 W. Bancroft · Structure no. 000000000023255

Built
1986
39 years old
Condition
Fair
inspected April 2022
Type
Frame
Concrete
Length
23 ft
1 main span
Daily traffic
50
2023 count
Owner
County
County Highway Agency

About this bridge

Nipper Road over Downy Marsh Valley Cnl is a concrete frame carrying Nipper Road over Downy Marsh Valley Cnl in Caribou County, Idaho. It was built in 1986, so it is 39 years old, younger 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 50 vehicles a day, roughly 10% of them trucks, projected to reach 75 by 2039. The structure is 23 ft (7 m) long and 48 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesNipper Road
CrossesDowny Marsh Valley Cnl
Location5.6 N. 3.1 W. Bancroft
RouteCounty Highway 0
CountyCaribou County
StateIdaho
Coordinates42.8022, -111.9483
Functional classRural Local

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 protection7 GoodSome minor problems.
Last inspectionApril 2022
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating72 US tons
Inventory rating43 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length23 ft (7 m)
Longest span23 ft (7 m)
Deck width48 ft (14.5 m)
Roadway width47 ft (14.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (2023)
Projected traffic75 by 2039
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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 Nipper Road over Downy Marsh Valley Cnl built?

It was built in 1986, making it 39 years old in 2025.

What condition is Nipper Road over Downy Marsh Valley Cnl 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 April 2022.

How much traffic does Nipper Road over Downy Marsh Valley Cnl carry?

About 50 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is Nipper Road over Downy Marsh Valley Cnl?

The structure is 23 ft (7 m) long with a longest span of 23 ft (7 m) and a deck 48 ft wide.

Who owns Nipper Road over Downy Marsh Valley Cnl?

It is owned by the County Highway Agency.