US Bridges

R70/580th Ave over Small Stream

Fair

Story County, Iowa · 083233302 · Structure no. 000000000314821

Built
1987
38 years old
Condition
Fair
inspected January 2023
Type
Culvert
Concrete Continuous
Length
38 ft
3 main spans
Daily traffic
820
2023 count
Owner
County
County Highway Agency

About this bridge

R70/580th Ave over Small Stream is a concrete continuous culvert carrying R70/580th Ave over Small Stream in Story County, Iowa. It was built in 1987, so it is 38 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 820 vehicles a day, projected to reach 820 by 2043. The structure is 38 ft (11.6 m) long. If it were closed, the detour would be 11.8 mi (19 km).

Location

Open in Google Maps
CarriesR70/580th Ave
CrossesSmall Stream
Location083233302
RouteCounty Highway 0
CountyStory County
StateIowa
Coordinates41.96473, -93.54106
Functional classRural Minor Collector

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 protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 rating110.1 US tons
Inventory rating110.1 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans3
Design loadHS 20
Structure length38 ft (11.6 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 traffic820 (2023)
Projected traffic820 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.8 mi (19 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 R70/580th Ave over Small Stream built?

It was built in 1987, making it 38 years old in 2025.

What condition is R70/580th Ave over Small Stream 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 R70/580th Ave over Small Stream carry?

About 820 vehicles per day (2023 count).

How long is R70/580th Ave over Small Stream?

The structure is 38 ft (11.6 m) long with a longest span of 12 ft (3.7 m).

Who owns R70/580th Ave over Small Stream?

It is owned by the County Highway Agency.