US Bridges

FM over Tarkio Creek

PoorPosted for load

Montgomery County, Iowa · 071370405 · Structure no. 000000000254390

Built
1949
76 years old
Condition
Poor
inspected May 2024
Type
Truss - Thru
Steel
Length
144 ft
1 main span
Daily traffic
159
2022 count
Owner
County
County Highway Agency

About this bridge

FM over Tarkio Creek is a steel truss - thru carrying FM over Tarkio Creek in Montgomery County, Iowa. It was built in 1949, so it is 76 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 159 vehicles a day, projected to reach 159 by 2044. The structure is 144 ft (43.9 m) long and 21 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesFM
CrossesTarkio Creek
Location071370405
RouteCounty Highway 0
StateIowa
Coordinates40.98037, -95.11476
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
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation2: Basically intolerable, requiring high priority of replacement
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating19.4 US tons
Inventory rating10.7 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckConcrete, cast-in-place
Main spans1 (+2 approach)
Design loadUnknown
Structure length144 ft (43.9 m)
Longest span90 ft (27.4 m)
Deck width21 ft (6.4 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic159 (2022)
Projected traffic159 by 2044
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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 Tarkio Creek built?

It was built in 1949, making it 76 years old in 2025.

What condition is FM over Tarkio 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 May 2024.

How much traffic does FM over Tarkio Creek carry?

About 159 vehicles per day (2022 count).

How long is FM over Tarkio Creek?

The structure is 144 ft (43.9 m) long with a longest span of 90 ft (27.4 m) and a deck 21 ft wide.

Who owns FM over Tarkio Creek?

It is owned by the County Highway Agency.