US Bridges

County Highway over Big Slough

FairPosted for load

Otoe County, Nebraska · 6.8N 3.6E Dunbar · Structure no. C006610490

Built
1935
90 years old
Condition
Fair
inspected October 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
56 ft
2 main spans
Daily traffic
30
2003 count
Owner
County
County Highway Agency

About this bridge

County Highway over Big Slough is a steel stringer/multi-beam or girder carrying County Highway over Big Slough in Otoe County, Nebraska. It was built in 1935, so it is 90 years old, older than the Nebraska average of 47.1 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. Its operating status is: posted for load restriction.

It carries about 30 vehicles a day, projected to reach 51 by 2033. The structure is 56 ft (17.1 m) long and 16 ft wide. If it were closed, the detour would be 31.1 mi (50 km).

Location

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CarriesCounty Highway
CrossesBig Slough
Location6.8N 3.6E Dunbar
RouteCounty Highway 104
CountyOtoe County
StateNebraska
Coordinates40.7697, -95.9526
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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation2: Basically intolerable, requiring high priority of replacement
Deck geometry7: Better than present minimum criteria
Waterway adequacy4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating3.3 US tons
Inventory rating2.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckWood or timber
Main spans2
Design loadUnknown
Structure length56 ft (17.1 m)
Longest span35 ft (10.7 m)
Deck width16 ft (4.9 m)
Roadway width15 ft (4.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic30 (2003)
Projected traffic51 by 2033
Trucks0%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed31.1 mi (50 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was County Highway over Big Slough built?

It was built in 1935, making it 90 years old in 2025.

What condition is County Highway over Big Slough 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 October 2023.

How much traffic does County Highway over Big Slough carry?

About 30 vehicles per day (2003 count).

How long is County Highway over Big Slough?

The structure is 56 ft (17.1 m) long with a longest span of 35 ft (10.7 m) and a deck 16 ft wide.

Who owns County Highway over Big Slough?

It is owned by the County Highway Agency.