US Bridges

I 29 Ia 12 NB over Perry Creek Conduit

Good

Woodbury County, Iowa · 0.1 MI S of JCT US 77 · Structure no. 000000000700345

Built
2017
8 years old, rebuilt 2020
Condition
Good
inspected September 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
89 ft
1 main span
Daily traffic
16,450
2022 count
Owner
State
State Highway Agency

About this bridge

I 29 Ia 12 NB over Perry Creek Conduit is a prestressed concrete stringer/multi-beam or girder carrying I 29 Ia 12 NB over Perry Creek Conduit in Woodbury County, Iowa. It was built in 2017 and reconstructed in 2020, so it is 8 years old, younger 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 16,450 vehicles a day, roughly 19% of them trucks, projected to reach 16,450 by 2043. The structure is 89 ft (27 m) long and 65 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI 29 Ia 12 NB
CrossesPerry Creek Conduit
Location0.1 MI S of JCT US 77
RouteInterstate 29
CountyWoodbury County
StateIowa
Coordinates42.49098, -96.4109
Functional classUrban Principal Arterial - Interstate

Condition and inspection

Good

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46.4 US tons
Inventory rating35.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length89 ft (27 m)
Longest span85 ft (25.9 m)
Deck width65 ft (19.7 m)
Roadway width61 ft (18.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic16,450 (2022)
Projected traffic16,450 by 2043
Trucks19%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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 I 29 Ia 12 NB over Perry Creek Conduit built?

It was built in 2017, making it 8 years old in 2025. It was reconstructed in 2020.

What condition is I 29 Ia 12 NB over Perry Creek Conduit 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 September 2023.

How much traffic does I 29 Ia 12 NB over Perry Creek Conduit carry?

About 16,450 vehicles per day (2022 count), of which roughly 19% are trucks.

How long is I 29 Ia 12 NB over Perry Creek Conduit?

The structure is 89 ft (27 m) long with a longest span of 85 ft (25.9 m) and a deck 65 ft wide.

Who owns I 29 Ia 12 NB over Perry Creek Conduit?

It is owned by the State Highway Agency.