US Bridges

FM 120th ST over Hoosier Creek

Fair

Johnson County, Iowa · 081060509 · Structure no. 000000000205490

Built
1900
125 years old, rebuilt 1993
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
153 ft
3 main spans
Daily traffic
1,500
2021 count
Owner
County
County Highway Agency

About this bridge

FM 120th ST over Hoosier Creek is a steel continuous stringer/multi-beam or girder carrying FM 120th ST over Hoosier Creek in Johnson County, Iowa. It was built in 1900 and reconstructed in 1993, so it is 125 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 1,500 vehicles a day, roughly 14% of them trucks, projected to reach 1,500 by 2043. The structure is 153 ft (46.6 m) long and 33 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesFM 120th ST
CrossesHoosier Creek
Location081060509
RouteCounty Highway 0
CountyJohnson County
StateIowa
Coordinates41.84805, -91.56767
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 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
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating43 US tons
Inventory rating28.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length153 ft (46.6 m)
Longest span59 ft (18 m)
Deck width33 ft (10.1 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,500 (2021)
Projected traffic1,500 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was FM 120th ST over Hoosier Creek built?

It was built in 1900, making it 125 years old in 2025. It was reconstructed in 1993.

What condition is FM 120th ST over Hoosier Creek 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 April 2023.

How much traffic does FM 120th ST over Hoosier Creek carry?

About 1,500 vehicles per day (2021 count), of which roughly 14% are trucks.

How long is FM 120th ST over Hoosier Creek?

The structure is 153 ft (46.6 m) long with a longest span of 59 ft (18 m) and a deck 33 ft wide.

Who owns FM 120th ST over Hoosier Creek?

It is owned by the County Highway Agency.