US Bridges

NB I-29 over Drainage Ditch

Fair

Pottawattamie County, Iowa · 0.3 Mi. N of Jct. Ia 192 · Structure no. 000000000044880

Built
1958
67 years old, rebuilt 1969
Condition
Fair
inspected May 2023
Type
Culvert
Concrete Continuous
Length
23 ft
2 main spans
Daily traffic
7,100
2022 count
Owner
State
State Highway Agency

About this bridge

NB I-29 over Drainage Ditch is a concrete continuous culvert carrying NB I-29 over Drainage Ditch in Pottawattamie County, Iowa. It was built in 1958 and reconstructed in 1969, so it is 67 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 7,100 vehicles a day, roughly 20% of them trucks, projected to reach 7,100 by 2042. The structure is 23 ft (7 m) long. If it were closed, the detour would be 5 mi (8 km).

Location

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CarriesNB I-29
CrossesDrainage Ditch
Location0.3 Mi. N of Jct. Ia 192
RouteInterstate 29
CountyPottawattamie County
StateIowa
Coordinates41.28844, -95.86615
Functional classUrban Principal Arterial - Interstate

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 protection7 GoodSome minor problems.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no 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 alignment7: Better than present minimum criteria
Operating rating27 US tons
Inventory rating20 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadH 20
Structure length23 ft (7 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 traffic7,100 (2022)
Projected traffic7,100 by 2042
Trucks20%
Lanes on structure3
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 NB I-29 over Drainage Ditch built?

It was built in 1958, making it 67 years old in 2025. It was reconstructed in 1969.

What condition is NB I-29 over Drainage Ditch 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 May 2023.

How much traffic does NB I-29 over Drainage Ditch carry?

About 7,100 vehicles per day (2022 count), of which roughly 20% are trucks.

How long is NB I-29 over Drainage Ditch?

The structure is 23 ft (7 m) long with a longest span of 10 ft (3 m).

Who owns NB I-29 over Drainage Ditch?

It is owned by the State Highway Agency.