US Bridges

Ia 1 over South Walnut Creek

Fair

Jefferson County, Iowa · 5.8 Mi. S of S Jct. Ia 78 · Structure no. 000000000031400

Built
1969
56 years old
Condition
Fair
inspected December 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
204 ft
3 main spans
Daily traffic
2,560
2022 count
Owner
State
State Highway Agency

About this bridge

Ia 1 over South Walnut Creek is a prestressed concrete stringer/multi-beam or girder carrying Ia 1 over South Walnut Creek in Jefferson 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 2,560 vehicles a day, roughly 7% of them trucks, projected to reach 2,560 by 2043. The structure is 204 ft (62.2 m) long and 48 ft wide. If it were closed, the detour would be 29.8 mi (48 km).

Location

Open in Google Maps
CarriesIa 1
CrossesSouth Walnut Creek
Location5.8 Mi. S of S Jct. Ia 78
RouteState Highway 1
CountyJefferson County
StateIowa
Coordinates41.09435, -91.96721
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 protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionDecember 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 geometry7: Better than present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating75.4 US tons
Inventory rating33.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length204 ft (62.2 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 traffic2,560 (2022)
Projected traffic2,560 by 2043
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed29.8 mi (48 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 1 over South Walnut Creek built?

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

What condition is Ia 1 over South Walnut Creek 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 December 2023.

How much traffic does Ia 1 over South Walnut Creek carry?

About 2,560 vehicles per day (2022 count), of which roughly 7% are trucks.

How long is Ia 1 over South Walnut Creek?

The structure is 204 ft (62.2 m) long with a longest span of 82 ft (25 m) and a deck 48 ft wide.

Who owns Ia 1 over South Walnut Creek?

It is owned by the State Highway Agency.