US Bridges

Ill 336 NB over Rock Creek

Fair

Adams County, Illinois · 2MI N I172/24 Int · Structure no. 001008300000000

Built
1994
31 years old
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
229 ft
2 main spans
Daily traffic
5,800
2023 count
Owner
State
State Highway Agency

About this bridge

Ill 336 NB over Rock Creek is a prestressed concrete stringer/multi-beam or girder carrying Ill 336 NB over Rock Creek in Adams County, Illinois. It was built in 1994, so it is 31 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 5,800 vehicles a day, roughly 12% of them trucks, projected to reach 3,156 by 2046. The structure is 229 ft (69.8 m) long and 43 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesIll 336 NB
CrossesRock Creek
Location2MI N I172/24 Int
RouteState Highway 110
CountyAdams County
StateIllinois
Coordinates40.03587, -91.30465
Functional classRural Principal Arterial - Other

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.
Superstructure7 GoodSome minor problems.
Substructure8 Very GoodNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating94.2 US tons
Inventory rating52.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length229 ft (69.8 m)
Longest span113 ft (34.5 m)
Deck width43 ft (13.2 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,800 (2023)
Projected traffic3,156 by 2046
Trucks12%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

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 Ill 336 NB over Rock Creek built?

It was built in 1994, making it 31 years old in 2025.

What condition is Ill 336 NB 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 August 2023.

How much traffic does Ill 336 NB over Rock Creek carry?

About 5,800 vehicles per day (2023 count), of which roughly 12% are trucks.

How long is Ill 336 NB over Rock Creek?

The structure is 229 ft (69.8 m) long with a longest span of 113 ft (34.5 m) and a deck 43 ft wide.

Who owns Ill 336 NB over Rock Creek?

It is owned by the State Highway Agency.