US Bridges

FM over Coal Creek

FairPosted for load

Mahaska County, Iowa · 074170104 · Structure no. 000000000235860

Built
1948
77 years old
Condition
Fair
inspected December 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
124 ft
3 main spans
Daily traffic
80
2022 count
Owner
County
County Highway Agency

About this bridge

FM over Coal Creek is a steel continuous stringer/multi-beam or girder carrying FM over Coal Creek in Mahaska County, Iowa. It was built in 1948, so it is 77 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 80 vehicles a day, projected to reach 80 by 2044. The structure is 124 ft (37.8 m) long and 23 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesFM
CrossesCoal Creek
Location074170104
RouteCounty Highway 0
CountyMahaska County
StateIowa
Coordinates41.23741, -92.76493
Functional classRural Minor 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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionDecember 2024
Inspection intervalevery 24 months
Operating statusPosted for load 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 adequacy6: Equal to present minimum criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating27.2 US tons
Inventory rating18 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 15
Structure length124 ft (37.8 m)
Longest span47 ft (14.3 m)
Deck width23 ft (7.1 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic80 (2022)
Projected traffic80 by 2044
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 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 over Coal Creek built?

It was built in 1948, making it 77 years old in 2025.

What condition is FM over Coal 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 December 2024.

How much traffic does FM over Coal Creek carry?

About 80 vehicles per day (2022 count).

How long is FM over Coal Creek?

The structure is 124 ft (37.8 m) long with a longest span of 47 ft (14.3 m) and a deck 23 ft wide.

Who owns FM over Coal Creek?

It is owned by the County Highway Agency.