US Bridges

480th over Small Stream

Poor

Mitchell County, Iowa · 100182601 · Structure no. 000000000249201

Built
1984
41 years old
Condition
Poor
inspected December 2023
Type
Tee Beam
Concrete
Length
37 ft
1 main span
Daily traffic
216
2022 count
Owner
County
County Highway Agency

About this bridge

480th over Small Stream is a concrete tee beam carrying 480th over Small Stream in Mitchell County, Iowa. It was built in 1984, so it is 41 years old, younger than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 3 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 216 vehicles a day, roughly 8% of them trucks, projected to reach 216 by 2043. The structure is 37 ft (11.3 m) long and 32 ft wide. If it were closed, the detour would be 14.9 mi (24 km).

Location

Open in Google Maps
Carries480th
CrossesSmall Stream
Location100182601
RouteCounty Highway 0
CountyMitchell County
StateIowa
Coordinates43.4582, -92.94282
Functional classRural Major Collector

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure3 SeriousLoss of section, deterioration, spalling or scour have seriously affected primary structural components.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionDecember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating65 US tons
Inventory rating39 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length37 ft (11.3 m)
Longest span35 ft (10.7 m)
Deck width32 ft (9.8 m)
Roadway width30 ft (9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic216 (2022)
Projected traffic216 by 2043
Trucks8%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed14.9 mi (24 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 480th over Small Stream built?

It was built in 1984, making it 41 years old in 2025.

What condition is 480th over Small Stream in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in December 2023.

How much traffic does 480th over Small Stream carry?

About 216 vehicles per day (2022 count), of which roughly 8% are trucks.

How long is 480th over Small Stream?

The structure is 37 ft (11.3 m) long with a longest span of 35 ft (10.7 m) and a deck 32 ft wide.

Who owns 480th over Small Stream?

It is owned by the County Highway Agency.