US Bridges

N14 (310th Ave) over Drainage Ditch

Poor

Dickinson County, Iowa · 099350302 · Structure no. 000000000023760

Built
1948
77 years old
Condition
Poor
inspected April 2023
Type
Culvert
Concrete Continuous
Length
21 ft
2 main spans
Daily traffic
803
2021 count
Owner
County
County Highway Agency

About this bridge

N14 (310th Ave) over Drainage Ditch is a concrete continuous culvert carrying N14 (310th Ave) over Drainage Ditch in Dickinson County, Iowa. It was built in 1948, so it is 77 years old, older than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 803 vehicles a day, roughly 17% of them trucks, projected to reach 803 by 2043. The structure is 21 ft (6.4 m) long. If it were closed, the detour would be 13 mi (21 km).

Location

Open in Google Maps
CarriesN14 (310th Ave)
CrossesDrainage Ditch
Location099350302
RouteCounty Highway 0
CountyDickinson County
StateIowa
Coordinates43.42566, -94.97384
Functional classRural Major Collector

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionApril 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 alignment8: Equal to present desirable criteria
Operating rating25.6 US tons
Inventory rating18.7 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadH 15
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 traffic803 (2021)
Projected traffic803 by 2043
Trucks17%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed13 mi (21 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 N14 (310th Ave) over Drainage Ditch built?

It was built in 1948, making it 77 years old in 2025.

What condition is N14 (310th Ave) over Drainage Ditch in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in April 2023.

How much traffic does N14 (310th Ave) over Drainage Ditch carry?

About 803 vehicles per day (2021 count), of which roughly 17% are trucks.

How long is N14 (310th Ave) over Drainage Ditch?

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

Who owns N14 (310th Ave) over Drainage Ditch?

It is owned by the County Highway Agency.