US Bridges

Calkins Ave over Knapp CR

Good

Johnson County, Iowa · 081080402 · Structure no. 000000000205721

Built
2008
17 years old
Condition
Good
inspected April 2021
Type
Culvert
Concrete Continuous
Length
21 ft
2 main spans
Daily traffic
49
2022 count
Owner
County
County Highway Agency

About this bridge

Calkins Ave over Knapp CR is a concrete continuous culvert carrying Calkins Ave over Knapp CR in Johnson County, Iowa. It was built in 2008, so it is 17 years old, younger than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 49 vehicles a day, roughly 35% of them trucks, projected to reach 49 by 2043. The structure is 21 ft (6.4 m) long. If it were closed, the detour would be 3.7 mi (6 km).

Location

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CarriesCalkins Ave
CrossesKnapp CR
Location081080402
RouteCounty Highway 0
CountyJohnson County
StateIowa
Coordinates41.85987, -91.79251
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert7 GoodSome minor problems.
Last inspectionApril 2021
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating51.5 US tons
Inventory rating39.7 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadHL 93
Structure length21 ft (6.4 m)
Longest span10 ft (3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic49 (2022)
Projected traffic49 by 2043
Trucks35%
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 statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Calkins Ave over Knapp CR built?

It was built in 2008, making it 17 years old in 2025.

What condition is Calkins Ave over Knapp CR in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in April 2021.

How much traffic does Calkins Ave over Knapp CR carry?

About 49 vehicles per day (2022 count), of which roughly 35% are trucks.

How long is Calkins Ave over Knapp CR?

The structure is 21 ft (6.4 m) long with a longest span of 10 ft (3 m).

Who owns Calkins Ave over Knapp CR?

It is owned by the County Highway Agency.