US Bridges

Spook Cave RD over Sm Stream

FairPosted for load

Clayton County, Iowa · 095041604 · Structure no. 000000000120990

Built
1954
71 years old
Condition
Fair
inspected October 2024
Type
Slab
Concrete
Length
25 ft
1 main span
Daily traffic
91
2022 count
Owner
County
County Highway Agency

About this bridge

Spook Cave RD over Sm Stream is a concrete slab carrying Spook Cave RD over Sm Stream in Clayton County, Iowa. It was built in 1954, so it is 71 years old, older than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 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 91 vehicles a day, projected to reach 91 by 2044. The structure is 25 ft (7.6 m) long and 23 ft wide. If it were closed, the detour would be 11.8 mi (19 km).

Location

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CarriesSpook Cave RD
CrossesSm Stream
Location095041604
RouteCounty Highway 0
CountyClayton County
StateIowa
Coordinates43.05062, -91.31502
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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating20.4 US tons
Inventory rating15.8 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length25 ft (7.6 m)
Longest span24 ft (7.3 m)
Deck width23 ft (6.9 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic91 (2022)
Projected traffic91 by 2044
Trucks0%
Lanes on structure2
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.8 mi (19 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 Spook Cave RD over Sm Stream built?

It was built in 1954, making it 71 years old in 2025.

What condition is Spook Cave RD over Sm Stream 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 2024.

How much traffic does Spook Cave RD over Sm Stream carry?

About 91 vehicles per day (2022 count).

How long is Spook Cave RD over Sm Stream?

The structure is 25 ft (7.6 m) long with a longest span of 24 ft (7.3 m) and a deck 23 ft wide.

Who owns Spook Cave RD over Sm Stream?

It is owned by the County Highway Agency.