US Bridges

Il 40 over Rock Creek

Fair

Carroll County, Illinois · 2 Mi. E. of Chadwick · Structure no. 008004400000000

Built
1995
30 years old
Condition
Fair
inspected March 2022
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
90 ft
2 main spans
Daily traffic
950
2023 count
Owner
State
State Highway Agency

About this bridge

Il 40 over Rock Creek is a prestressed concrete continuous stringer/multi-beam or girder carrying Il 40 over Rock Creek in Carroll County, Illinois. It was built in 1995, so it is 30 years old, younger 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 6 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 950 vehicles a day, roughly 12% of them trucks, projected to reach 1,061 by 2046. The structure is 90 ft (27.4 m) long and 35 ft wide. If it were closed, the detour would be 24.9 mi (40 km).

Location

Open in Google Maps
CarriesIl 40
CrossesRock Creek
Location2 Mi. E. of Chadwick
RouteState Highway 40
CountyCarroll County
StateIllinois
Coordinates42.00991, -89.84633
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMarch 2022
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating78.6 US tons
Inventory rating48.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20 + Mod
Structure length90 ft (27.4 m)
Longest span44 ft (13.4 m)
Deck width35 ft (10.7 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic950 (2023)
Projected traffic1,061 by 2046
Trucks12%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed24.9 mi (40 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 Il 40 over Rock Creek built?

It was built in 1995, making it 30 years old in 2025.

What condition is Il 40 over Rock 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 March 2022.

How much traffic does Il 40 over Rock Creek carry?

About 950 vehicles per day (2023 count), of which roughly 12% are trucks.

How long is Il 40 over Rock Creek?

The structure is 90 ft (27.4 m) long with a longest span of 44 ft (13.4 m) and a deck 35 ft wide.

Who owns Il 40 over Rock Creek?

It is owned by the State Highway Agency.