US Bridges

FM over Small Stream

Fair

Lyon County, Iowa · 099472401 · Structure no. 000000000230450

Built
1968
57 years old
Condition
Fair
inspected July 2023
Type
Culvert
Concrete Continuous
Length
32 ft
3 main spans
Daily traffic
729
2022 count
Owner
County
County Highway Agency

About this bridge

FM over Small Stream is a concrete continuous culvert carrying FM over Small Stream in Lyon County, Iowa. It was built in 1968, so it is 57 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.

It carries about 729 vehicles a day, roughly 14% of them trucks, projected to reach 729 by 2043. The structure is 32 ft (9.8 m) long. If it were closed, the detour would be 3.1 mi (5 km).

CarriesFM
CrossesSmall Stream
Location099472401
RouteCounty Highway 0
StateIowa
Coordinates43.38949, -96.34093
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
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: 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 rating36 US tons
Inventory rating27 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans3
Design loadH 20
Structure length32 ft (9.8 m)
Longest span10 ft (3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic729 (2022)
Projected traffic729 by 2043
Trucks14%
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 proposedOther structural work, including hydraulic replacements
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was FM over Small Stream built?

It was built in 1968, making it 57 years old in 2025.

What condition is FM 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 July 2023.

How much traffic does FM over Small Stream carry?

About 729 vehicles per day (2022 count), of which roughly 14% are trucks.

How long is FM over Small Stream?

The structure is 32 ft (9.8 m) long with a longest span of 10 ft (3 m).

Who owns FM over Small Stream?

It is owned by the County Highway Agency.