US Bridges

FM over Olive Branch Creek

PoorPosted for load

Mahaska County, Iowa · 074140103 · Structure no. 000000000235340

Built
1950
75 years old
Condition
Poor
inspected December 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
54 ft
1 main span
Daily traffic
30
2022 count
Owner
County
County Highway Agency

About this bridge

FM over Olive Branch Creek is a steel stringer/multi-beam or girder carrying FM over Olive Branch Creek in Mahaska County, Iowa. It was built in 1950, so it is 75 years old, older 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 4 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. Its operating status is: posted for load restriction.

It carries about 30 vehicles a day, projected to reach 30 by 2043. The structure is 54 ft (16.5 m) long and 22 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

CarriesFM
CrossesOlive Branch Creek
Location074140103
RouteCounty Highway 0
StateIowa
Coordinates41.24986, -92.41429
Functional classRural Minor 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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionDecember 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry5: 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 rating21.2 US tons
Inventory rating13.8 US tons

Structure

MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length54 ft (16.5 m)
Longest span51 ft (15.5 m)
Deck width22 ft (6.7 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic30 (2022)
Projected traffic30 by 2043
Trucks0%
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 over Olive Branch Creek built?

It was built in 1950, making it 75 years old in 2025.

What condition is FM over Olive Branch Creek 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 FM over Olive Branch Creek carry?

About 30 vehicles per day (2022 count).

How long is FM over Olive Branch Creek?

The structure is 54 ft (16.5 m) long with a longest span of 51 ft (15.5 m) and a deck 22 ft wide.

Who owns FM over Olive Branch Creek?

It is owned by the County Highway Agency.