US Bridges

FM M-66 over Creek

Fair

Audubon County, Iowa · 080360808 · Structure no. 000000000068730

Built
1958
67 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
183 ft
3 main spans
Daily traffic
338
2022 count
Owner
County
County Highway Agency

About this bridge

FM M-66 over Creek is a prestressed concrete stringer/multi-beam or girder carrying FM M-66 over Creek in Audubon County, Iowa. It was built in 1958, so it is 67 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 338 vehicles a day, roughly 10% of them trucks, projected to reach 338 by 2044. The structure is 183 ft (55.8 m) long and 26 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesFM M-66
CrossesCreek
Location080360808
RouteCounty Highway 0
CountyAudubon County
StateIowa
Coordinates41.7468, -95.07301
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.
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 protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionAugust 2024
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 adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating45.2 US tons
Inventory rating20 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadH 15
Structure length183 ft (55.8 m)
Longest span69 ft (21 m)
Deck width26 ft (8 m)
Roadway width24 ft (7.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic338 (2022)
Projected traffic338 by 2044
Trucks10%
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 M-66 over Creek built?

It was built in 1958, making it 67 years old in 2025.

What condition is FM M-66 over 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 August 2024.

How much traffic does FM M-66 over Creek carry?

About 338 vehicles per day (2022 count), of which roughly 10% are trucks.

How long is FM M-66 over Creek?

The structure is 183 ft (55.8 m) long with a longest span of 69 ft (21 m) and a deck 26 ft wide.

Who owns FM M-66 over Creek?

It is owned by the County Highway Agency.