US Bridges

Local over Knotty Creek

Fair

Des Moines County, Iowa · 071032501 · Structure no. 000000000143730

Built
1972
53 years old
Condition
Fair
inspected September 2024
Type
Tee Beam
Prestressed Concrete
Length
41 ft
1 main span
Daily traffic
123
2022 count
Owner
County
County Highway Agency

About this bridge

Local over Knotty Creek is a prestressed concrete tee beam carrying Local over Knotty Creek in Des Moines County, Iowa. It was built in 1972, so it is 53 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.

It carries about 123 vehicles a day, projected to reach 123 by 2044. The structure is 41 ft (12.5 m) long and 20 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesLocal
CrossesKnotty Creek
Location071032501
RouteCounty Highway 0
CountyDes Moines County
StateIowa
Coordinates40.92225, -91.14548
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2024
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 geometry4: 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 rating54 US tons
Inventory rating29.5 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadH 20
Structure length41 ft (12.5 m)
Longest span40 ft (12.2 m)
Deck width20 ft (6.1 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic123 (2022)
Projected traffic123 by 2044
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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 Local over Knotty Creek built?

It was built in 1972, making it 53 years old in 2025.

What condition is Local over Knotty 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 September 2024.

How much traffic does Local over Knotty Creek carry?

About 123 vehicles per day (2022 count).

How long is Local over Knotty Creek?

The structure is 41 ft (12.5 m) long with a longest span of 40 ft (12.2 m) and a deck 20 ft wide.

Who owns Local over Knotty Creek?

It is owned by the County Highway Agency.