US Bridges

Ia 31 over Ashton Creek

Fair

Ida County, Iowa · 1.0 Mi. N of SR D15 · Structure no. 000000000029181

Built
1974
51 years old
Condition
Fair
inspected October 2023
Type
Slab
Concrete Continuous
Length
133 ft
3 main spans
Daily traffic
1,600
2022 count
Owner
State
State Highway Agency

About this bridge

Ia 31 over Ashton Creek is a concrete continuous slab carrying Ia 31 over Ashton Creek in Ida County, Iowa. It was built in 1974, so it is 51 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 5 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 1,600 vehicles a day, roughly 17% of them trucks, projected to reach 1,600 by 2043. The structure is 133 ft (40.5 m) long and 47 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesIa 31
CrossesAshton Creek
Location1.0 Mi. N of SR D15
RouteState Highway 31
CountyIda County
StateIowa
Coordinates42.53861, -95.7334
Functional classRural Minor Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry8: Equal to present desirable criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating73.4 US tons
Inventory rating43.8 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length133 ft (40.5 m)
Longest span51 ft (15.5 m)
Deck width47 ft (14.4 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,600 (2022)
Projected traffic1,600 by 2043
Trucks17%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 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 31 over Ashton Creek built?

It was built in 1974, making it 51 years old in 2025.

What condition is Ia 31 over Ashton 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 October 2023.

How much traffic does Ia 31 over Ashton Creek carry?

About 1,600 vehicles per day (2022 count), of which roughly 17% are trucks.

How long is Ia 31 over Ashton Creek?

The structure is 133 ft (40.5 m) long with a longest span of 51 ft (15.5 m) and a deck 47 ft wide.

Who owns Ia 31 over Ashton Creek?

It is owned by the State Highway Agency.