US Bridges

FM over Blackhawk Creek

Poor

Grundy County, Iowa · 088173602 · Structure no. 000000000165231

Built
1971
54 years old
Condition
Poor
inspected March 2024
Type
Slab
Concrete Continuous
Length
128 ft
3 main spans
Daily traffic
1,935
2022 count
Owner
County
County Highway Agency

About this bridge

FM over Blackhawk Creek is a concrete continuous slab carrying FM over Blackhawk Creek in Grundy County, Iowa. It was built in 1971, so it is 54 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.

It carries about 1,935 vehicles a day, projected to reach 1,935 by 2044. The structure is 128 ft (39 m) long and 32 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

CarriesFM
CrossesBlackhawk Creek
Location088173602
RouteCounty Highway 0
StateIowa
Coordinates42.38377, -92.78777
Functional classRural Major 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.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
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 inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusOpen, no 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 adequacy6: Equal to present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating57 US tons
Inventory rating33 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 20
Structure length128 ft (39 m)
Longest span49 ft (14.9 m)
Deck width32 ft (9.8 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,935 (2022)
Projected traffic1,935 by 2044
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 Blackhawk Creek built?

It was built in 1971, making it 54 years old in 2025.

What condition is FM over Blackhawk 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 March 2024.

How much traffic does FM over Blackhawk Creek carry?

About 1,935 vehicles per day (2022 count).

How long is FM over Blackhawk Creek?

The structure is 128 ft (39 m) long with a longest span of 49 ft (14.9 m) and a deck 32 ft wide.

Who owns FM over Blackhawk Creek?

It is owned by the County Highway Agency.