US Bridges

620th AVE/S14 over Grant Open Ditch Ext 5

Fair

Story County, Iowa · 083223102 · Structure no. 000000000314661

Built
1977
48 years old
Condition
Fair
inspected December 2022
Type
Stringer/Multi-beam or Girder
Steel
Length
54 ft
1 main span
Daily traffic
988
2022 count
Owner
County
County Highway Agency

About this bridge

620th AVE/S14 over Grant Open Ditch Ext 5 is a steel stringer/multi-beam or girder carrying 620th AVE/S14 over Grant Open Ditch Ext 5 in Story County, Iowa. It was built in 1977, so it is 48 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 988 vehicles a day, roughly 10% of them trucks, projected to reach 988 by 2043. The structure is 54 ft (16.5 m) long and 30 ft wide. If it were closed, the detour would be 13 mi (21 km).

Location

Open in Google Maps
Carries620th AVE/S14
CrossesGrant Open Ditch Ext 5
Location083223102
RouteCounty Highway 0
CountyStory County
StateIowa
Coordinates41.95626, -93.46323
Functional classRural Major 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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionDecember 2022
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating51.3 US tons
Inventory rating30.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadH 20
Structure length54 ft (16.5 m)
Longest span51 ft (15.5 m)
Deck width30 ft (9.1 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic988 (2022)
Projected traffic988 by 2043
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed13 mi (21 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 620th AVE/S14 over Grant Open Ditch Ext 5 built?

It was built in 1977, making it 48 years old in 2025.

What condition is 620th AVE/S14 over Grant Open Ditch Ext 5 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 December 2022.

How much traffic does 620th AVE/S14 over Grant Open Ditch Ext 5 carry?

About 988 vehicles per day (2022 count), of which roughly 10% are trucks.

How long is 620th AVE/S14 over Grant Open Ditch Ext 5?

The structure is 54 ft (16.5 m) long with a longest span of 51 ft (15.5 m) and a deck 30 ft wide.

Who owns 620th AVE/S14 over Grant Open Ditch Ext 5?

It is owned by the County Highway Agency.