US Bridges

Ia 31 over Silver Creek

Fair

Cherokee County, Iowa · 1.2 Mi. W of US 59 · Structure no. 000000000019530

Built
1949
76 years old
Condition
Fair
inspected July 2024
Type
Culvert
Concrete Continuous
Length
21 ft
2 main spans
Daily traffic
1,180
2022 count
Owner
State
State Highway Agency

About this bridge

Ia 31 over Silver Creek is a concrete continuous culvert carrying Ia 31 over Silver Creek in Cherokee County, Iowa. It was built in 1949, so it is 76 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 1,180 vehicles a day, roughly 23% of them trucks, projected to reach 1,180 by 2044. The structure is 21 ft (6.4 m) long. If it were closed, the detour would be 6.8 mi (11 km).

Location

Open in Google Maps
CarriesIa 31
CrossesSilver Creek
Location1.2 Mi. W of US 59
RouteState Highway 31
CountyCherokee County
StateIowa
Coordinates42.63405, -95.58272
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
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating27 US tons
Inventory rating20 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadH 20
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 traffic1,180 (2022)
Projected traffic1,180 by 2044
Trucks23%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.8 mi (11 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 Silver Creek built?

It was built in 1949, making it 76 years old in 2025.

What condition is Ia 31 over Silver 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 July 2024.

How much traffic does Ia 31 over Silver Creek carry?

About 1,180 vehicles per day (2022 count), of which roughly 23% are trucks.

How long is Ia 31 over Silver Creek?

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

Who owns Ia 31 over Silver Creek?

It is owned by the State Highway Agency.