US Bridges

Ia 31 over Silver Creek

Fair

Cherokee County, Iowa · 1.0 Mi. W of US 59 · Structure no. 000000000019540

Built
1950
75 years old
Condition
Fair
inspected May 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
154 ft
3 main spans
Daily traffic
1,180
2022 count
Owner
State
State Highway Agency

About this bridge

Ia 31 over Silver Creek is a steel continuous stringer/multi-beam or girder carrying Ia 31 over Silver Creek in Cherokee County, Iowa. It was built in 1950, so it is 75 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 1,180 vehicles a day, roughly 23% of them trucks, projected to reach 1,180 by 2044. The structure is 154 ft (46.9 m) long and 32 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesIa 31
CrossesSilver Creek
Location1.0 Mi. W of US 59
RouteState Highway 31
CountyCherokee County
StateIowa
Coordinates42.63402, -95.57449
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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating43.2 US tons
Inventory rating25.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 20
Structure length154 ft (46.9 m)
Longest span59 ft (18 m)
Deck width32 ft (9.8 m)
Roadway width26 ft (7.9 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 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 Silver Creek built?

It was built in 1950, making it 75 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 May 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 154 ft (46.9 m) long with a longest span of 59 ft (18 m) and a deck 32 ft wide.

Who owns Ia 31 over Silver Creek?

It is owned by the State Highway Agency.