Ia 4 over Drainage Ditch

Good

Palo Alto County, Iowa · 3.0 Mi. N of N Jct. US 18 · Structure no. 000000000039231

Built: 1976; 49 years old
Condition: Good; inspected August 2023
Type: Culvert; Concrete Continuous
Length: 27 ft; 2 main spans
Daily traffic: 2,010; 2022 count
Owner: State; State Highway Agency

About this bridge

Ia 4 over Drainage Ditch is a concrete continuous culvert carrying Ia 4 over Drainage Ditch in Palo Alto County, Iowa. It was built in 1976, so it is 49 years old, older 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 2,010 vehicles a day, roughly 14% of them trucks, projected to reach 2,010 by 2043. The structure is 27 ft (8.2 m) long and 46 ft wide. If it were closed, the detour would be 14.3 mi (23 km).

Location

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CarriesIa 4

CrossesDrainage Ditch

Location3.0 Mi. N of N Jct. US 18

RouteState Highway 4

CountyPalo Alto County

StateIowa

Coordinates43.17103, -94.75757

Functional classRural Minor Arterial

Condition and inspection

Good

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

Component	Rating	Meaning
Channel and channel protection	7 Good	Some minor problems.
Culvert	7 Good	Some minor problems.

Last inspectionAugust 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 adequacy7: Better than present minimum criteria

Approach roadway alignment8: Equal to present desirable criteria

Operating rating39.9 US tons

Inventory rating23.9 US tons

Structure

Structure typeCulvert

MaterialConcrete Continuous

DeckConcrete, cast-in-place

Main spans2

Design loadHS 20

Structure length27 ft (8.2 m)

Longest span12 ft (3.7 m)

Deck width46 ft (14.1 m)

Roadway width40 ft (12.2 m)

Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,010 (2022)

Projected traffic2,010 by 2043

Trucks14%

Lanes on structure2

Traffic directionTwo-way traffic

CarriesHighway

CrossesWaterway

Detour if closed14.3 mi (23 km)

TollOn a free road

National Highway SystemNo

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 Ia 4 over Drainage Ditch built?

It was built in 1976, making it 49 years old in 2025.

What condition is Ia 4 over Drainage Ditch 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 August 2023.

How much traffic does Ia 4 over Drainage Ditch carry?

About 2,010 vehicles per day (2022 count), of which roughly 14% are trucks.

How long is Ia 4 over Drainage Ditch?

The structure is 27 ft (8.2 m) long with a longest span of 12 ft (3.7 m) and a deck 46 ft wide.

Who owns Ia 4 over Drainage Ditch?

It is owned by the State Highway Agency.