US Bridges

S14 620th Ave over Calamus Creek

Good

Story County, Iowa · 0.4 MI N 305th ST · Structure no. 000000000313751

Built
2023
2 years old
Condition
Good
inspected December 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
52 ft
1 main span
Daily traffic
988
2022 count
Owner
County
County Highway Agency

About this bridge

S14 620th Ave over Calamus Creek is a prestressed concrete stringer/multi-beam or girder carrying S14 620th Ave over Calamus Creek in Story County, Iowa. It was built in 2023, so it is 2 years old, younger than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 988 vehicles a day, roughly 10% of them trucks, projected to reach 988 by 2042. The structure is 52 ft (15.9 m) long and 33 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesS14 620th Ave
CrossesCalamus Creek
Location0.4 MI N 305th ST
RouteCounty Highway 0
CountyStory County
StateIowa
Coordinates41.91994, -93.46336
Functional classRural Major Collector

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionDecember 2023
Inspection intervalevery 3 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating64.3 US tons
Inventory rating47.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length52 ft (15.9 m)
Longest span52 ft (15.9 m)
Deck width33 ft (10.2 m)
Roadway width31 ft (9.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic988 (2022)
Projected traffic988 by 2042
Trucks10%
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 S14 620th Ave over Calamus Creek built?

It was built in 2023, making it 2 years old in 2025.

What condition is S14 620th Ave over Calamus Creek in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in December 2023.

How much traffic does S14 620th Ave over Calamus Creek carry?

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

How long is S14 620th Ave over Calamus Creek?

The structure is 52 ft (15.9 m) long with a longest span of 52 ft (15.9 m) and a deck 33 ft wide.

Who owns S14 620th Ave over Calamus Creek?

It is owned by the County Highway Agency.