US Bridges

Ia 330 NB over North Skunk River

Fair

Marshall County, Iowa · 0.8 Mi. N of Jct. SR S-52 · Structure no. 000000000035620

Built
1969
56 years old
Condition
Fair
inspected November 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
218 ft
3 main spans
Daily traffic
8,300
2022 count
Owner
State
State Highway Agency

About this bridge

Ia 330 NB over North Skunk River is a steel continuous stringer/multi-beam or girder carrying Ia 330 NB over North Skunk River in Marshall County, Iowa. It was built in 1969, so it is 56 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 8,300 vehicles a day, roughly 18% of them trucks, projected to reach 8,300 by 2043. The structure is 218 ft (66.4 m) long and 48 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesIa 330 NB
CrossesNorth Skunk River
Location0.8 Mi. N of Jct. SR S-52
RouteState Highway 330
CountyMarshall County
StateIowa
Coordinates41.91834, -93.15142
Functional classRural Principal Arterial - Other

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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating49.7 US tons
Inventory rating30.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length218 ft (66.4 m)
Longest span82 ft (25 m)
Deck width48 ft (14.5 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,300 (2022)
Projected traffic8,300 by 2043
Trucks18%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

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 330 NB over North Skunk River built?

It was built in 1969, making it 56 years old in 2025.

What condition is Ia 330 NB over North Skunk River 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 November 2023.

How much traffic does Ia 330 NB over North Skunk River carry?

About 8,300 vehicles per day (2022 count), of which roughly 18% are trucks.

How long is Ia 330 NB over North Skunk River?

The structure is 218 ft (66.4 m) long with a longest span of 82 ft (25 m) and a deck 48 ft wide.

Who owns Ia 330 NB over North Skunk River?

It is owned by the State Highway Agency.