US Bridges

140th ST NW over Knapp Creek

Fair

Johnson County, Iowa · 081081601 · Structure no. 000000000205821

Built
1987
38 years old
Condition
Fair
inspected April 2023
Type
Slab
Concrete Continuous
Length
128 ft
3 main spans
Daily traffic
50
2021 count
Owner
County
County Highway Agency

About this bridge

140th ST NW over Knapp Creek is a concrete continuous slab carrying 140th ST NW over Knapp Creek in Johnson County, Iowa. It was built in 1987, so it is 38 years old, younger 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 50 vehicles a day, projected to reach 50 by 2043. The structure is 128 ft (39 m) long and 24 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
Carries140th ST NW
CrossesKnapp Creek
Location081081601
RouteCounty Highway 0
CountyJohnson County
StateIowa
Coordinates41.83299, -91.78925
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.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating62.4 US tons
Inventory rating21.4 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length128 ft (39 m)
Longest span49 ft (14.9 m)
Deck width24 ft (7.3 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (2021)
Projected traffic50 by 2043
Trucks0%
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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was 140th ST NW over Knapp Creek built?

It was built in 1987, making it 38 years old in 2025.

What condition is 140th ST NW over Knapp Creek 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 2023.

How much traffic does 140th ST NW over Knapp Creek carry?

About 50 vehicles per day (2021 count).

How long is 140th ST NW over Knapp Creek?

The structure is 128 ft (39 m) long with a longest span of 49 ft (14.9 m) and a deck 24 ft wide.

Who owns 140th ST NW over Knapp Creek?

It is owned by the County Highway Agency.