US Bridges

Keystone RD over Stream

Fair

Clayton County, Iowa · 094030803 · Structure no. 000000000120190

Built
1925
100 years old
Condition
Fair
inspected October 2024
Type
Culvert
Concrete
Length
27 ft
2 main spans
Daily traffic
62
2022 count
Owner
County
County Highway Agency

About this bridge

Keystone RD over Stream is a concrete culvert carrying Keystone RD over Stream in Clayton County, Iowa. It was built in 1925, so it is 100 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 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 62 vehicles a day, projected to reach 62 by 2044. The structure is 27 ft (8.2 m) long and 22 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesKeystone RD
CrossesStream
Location094030803
RouteCounty Highway 0
CountyClayton County
StateIowa
Coordinates42.9685, -91.22436
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
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating25.6 US tons
Inventory rating18.7 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckConcrete, cast-in-place
Main spans2
Design loadUnknown
Structure length27 ft (8.2 m)
Longest span12 ft (3.7 m)
Deck width22 ft (6.6 m)
Roadway width20 ft (6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic62 (2022)
Projected traffic62 by 2044
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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 Keystone RD over Stream built?

It was built in 1925, making it 100 years old in 2025.

What condition is Keystone RD over 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 Keystone RD over Stream carry?

About 62 vehicles per day (2022 count).

How long is Keystone RD over Stream?

The structure is 27 ft (8.2 m) long with a longest span of 12 ft (3.7 m) and a deck 22 ft wide.

Who owns Keystone RD over Stream?

It is owned by the County Highway Agency.