US Bridges

FM over Porter Creek

Fair

Sac County, Iowa · 086383504 · Structure no. 000000000299750

Built
1960
65 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
59 ft
1 main span
Daily traffic
100
2022 count
Owner
County
County Highway Agency

About this bridge

FM over Porter Creek is a steel stringer/multi-beam or girder carrying FM over Porter Creek in Sac County, Iowa. It was built in 1960, so it is 65 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 100 vehicles a day, roughly 12% of them trucks, projected to reach 100 by 2044. The structure is 59 ft (18 m) long and 26 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesFM
CrossesPorter Creek
Location086383504
RouteCounty Highway 0
CountySac County
StateIowa
Coordinates42.21616, -95.24591
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
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 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 geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating39.6 US tons
Inventory rating23.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadH 20
Structure length59 ft (18 m)
Longest span57 ft (17.4 m)
Deck width26 ft (7.9 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic100 (2022)
Projected traffic100 by 2044
Trucks12%
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 proposedOther structural work, including hydraulic replacements
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was FM over Porter Creek built?

It was built in 1960, making it 65 years old in 2025.

What condition is FM over Porter 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 over Porter Creek carry?

About 100 vehicles per day (2022 count), of which roughly 12% are trucks.

How long is FM over Porter Creek?

The structure is 59 ft (18 m) long with a longest span of 57 ft (17.4 m) and a deck 26 ft wide.

Who owns FM over Porter Creek?

It is owned by the County Highway Agency.