US Bridges

Big Rock RD over Creek

PoorPosted for load

Scott County, Iowa · 080E10304 · Structure no. 000000000303010

Built
1923
102 years old, rebuilt 1970
Condition
Poor
inspected April 2024
Type
Slab
Concrete
Length
33 ft
1 main span
Daily traffic
1,060
2021 count
Owner
County
County Highway Agency

About this bridge

Big Rock RD over Creek is a concrete slab carrying Big Rock RD over Creek in Scott County, Iowa. It was built in 1923 and reconstructed in 1970, so it is 102 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 3 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 1,060 vehicles a day, roughly 13% of them trucks, projected to reach 1,060 by 2044. The structure is 33 ft (10.1 m) long and 28 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

CarriesBig Rock RD
CrossesCreek
Location080E10304
RouteCounty Highway 0
StateIowa
Coordinates41.77016, -90.82671
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.
Superstructure3 SeriousLoss of section, deterioration, spalling or scour have seriously affected primary structural components.
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 inspectionApril 2024
Inspection intervalevery 12 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating28 US tons
Inventory rating20 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length33 ft (10.1 m)
Longest span31 ft (9.4 m)
Deck width28 ft (8.6 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,060 (2021)
Projected traffic1,060 by 2044
Trucks13%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.8 mi (11 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 Big Rock RD over Creek built?

It was built in 1923, making it 102 years old in 2025. It was reconstructed in 1970.

What condition is Big Rock RD over 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 April 2024.

How much traffic does Big Rock RD over Creek carry?

About 1,060 vehicles per day (2021 count), of which roughly 13% are trucks.

How long is Big Rock RD over Creek?

The structure is 33 ft (10.1 m) long with a longest span of 31 ft (9.4 m) and a deck 28 ft wide.

Who owns Big Rock RD over Creek?

It is owned by the County Highway Agency.