US Bridges

Plank Road over Coon Creek

Fair

DeKalb County, Illinois · 2800N 1750E · Structure no. 019300200000000

Built
1941
84 years old, rebuilt 1980
Condition
Fair
inspected February 2024
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
22 ft
1 main span
Daily traffic
7,300
2021 count
Owner
County
County Highway Agency

About this bridge

Plank Road over Coon Creek is a prestressed concrete box beam or girders - multiple carrying Plank Road over Coon Creek in DeKalb County, Illinois. It was built in 1941 and reconstructed in 1980, so it is 84 years old, older than the Illinois average of 45.3 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 7,300 vehicles a day, roughly 8% of them trucks, projected to reach 8,176 by 2046. The structure is 22 ft (6.7 m) long and 43 ft wide. If it were closed, the detour would be 19.9 mi (32 km).

Location

Open in Google Maps
CarriesPlank Road
CrossesCoon Creek
Location2800N 1750E
RouteCounty Highway 0
CountyDeKalb County
StateIllinois
Coordinates42.04019, -88.60854
Functional classRural Minor Arterial

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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionFebruary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
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 adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating68.9 US tons
Inventory rating30.3 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHS 20
Structure length22 ft (6.7 m)
Longest span21 ft (6.4 m)
Deck width43 ft (13.2 m)
Roadway width41 ft (12.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,300 (2021)
Projected traffic8,176 by 2046
Trucks8%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed19.9 mi (32 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Plank Road over Coon Creek built?

It was built in 1941, making it 84 years old in 2025. It was reconstructed in 1980.

What condition is Plank Road over Coon 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 February 2024.

How much traffic does Plank Road over Coon Creek carry?

About 7,300 vehicles per day (2021 count), of which roughly 8% are trucks.

How long is Plank Road over Coon Creek?

The structure is 22 ft (6.7 m) long with a longest span of 21 ft (6.4 m) and a deck 43 ft wide.

Who owns Plank Road over Coon Creek?

It is owned by the County Highway Agency.