US Bridges

300th ST over Small Stream

FairPosted for load

Story County, Iowa · 082241303 · Structure no. 000000000314270

Built
1963
62 years old, rebuilt 1974
Condition
Fair
inspected January 2023
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
20 ft
1 main span
Daily traffic
100
2022 count
Owner
County
County Highway Agency

About this bridge

300th ST over Small Stream is a wood or timber stringer/multi-beam or girder carrying 300th ST over Small Stream in Story County, Iowa. It was built in 1963 and reconstructed in 1974, so it is 62 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. Its operating status is: posted for load restriction.

It carries about 100 vehicles a day, projected to reach 100 by 2043. The structure is 20 ft (6.1 m) long and 24 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
Carries300th ST
CrossesSmall Stream
Location082241303
RouteCounty Highway 0
CountyStory County
StateIowa
Coordinates41.92129, -93.58947
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJanuary 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating28 US tons
Inventory rating18 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadUnknown
Structure length20 ft (6.1 m)
Longest span18 ft (5.5 m)
Deck width24 ft (7.3 m)
Roadway width23 ft (7.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic100 (2022)
Projected traffic100 by 2043
Trucks0%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was 300th ST over Small Stream built?

It was built in 1963, making it 62 years old in 2025. It was reconstructed in 1974.

What condition is 300th ST 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 300th ST over Small Stream carry?

About 100 vehicles per day (2022 count).

How long is 300th ST over Small Stream?

The structure is 20 ft (6.1 m) long with a longest span of 18 ft (5.5 m) and a deck 24 ft wide.

Who owns 300th ST over Small Stream?

It is owned by the County Highway Agency.