US Bridges

310th ST over Rock Creek

Fair

Story County, Iowa · 082222301 · Structure no. 000000000313831

Built
1988
37 years old
Condition
Fair
inspected January 2023
Type
Culvert
Concrete Continuous
Length
27 ft
2 main spans
Daily traffic
40
2022 count
Owner
County
County Highway Agency

About this bridge

310th ST over Rock Creek is a concrete continuous culvert carrying 310th ST over Rock Creek in Story County, Iowa. It was built in 1988, so it is 37 years old, younger 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 40 vehicles a day, projected to reach 40 by 2043. The structure is 27 ft (8.2 m) long. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
Carries310th ST
CrossesRock Creek
Location082222301
RouteCounty Highway 0
CountyStory County
StateIowa
Coordinates41.90656, -93.37911
Functional classRural Local

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 inspectionJanuary 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating62.2 US tons
Inventory rating37.1 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadHS 20
Structure length27 ft (8.2 m)
Longest span12 ft (3.7 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic40 (2022)
Projected traffic40 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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 310th ST over Rock Creek built?

It was built in 1988, making it 37 years old in 2025.

What condition is 310th ST over Rock 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 January 2023.

How much traffic does 310th ST over Rock Creek carry?

About 40 vehicles per day (2022 count).

How long is 310th ST over Rock Creek?

The structure is 27 ft (8.2 m) long with a longest span of 12 ft (3.7 m).

Who owns 310th ST over Rock Creek?

It is owned by the County Highway Agency.