US Bridges

Rockton RD over Rock River Overflow

Fair

Winnebago County, Illinois · .3 MI W of Rockton · Structure no. 101308100000000

Built
1989
36 years old
Condition
Fair
inspected March 2022
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
219 ft
4 main spans
Daily traffic
2,200
2022 count
Owner
County
County Highway Agency

About this bridge

Rockton RD over Rock River Overflow is a prestressed concrete continuous stringer/multi-beam or girder carrying Rockton RD over Rock River Overflow in Winnebago County, Illinois. It was built in 1989, so it is 36 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 2,200 vehicles a day, roughly 5% of them trucks, projected to reach 2,273 by 2046. The structure is 219 ft (66.7 m) long and 35 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesRockton RD
CrossesRock River Overflow
Location.3 MI W of Rockton
CountyWinnebago County
StateIllinois
Coordinates42.45864, -89.09309
Functional classUrban Collector

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.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionMarch 2022
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating89.3 US tons
Inventory rating50.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length219 ft (66.7 m)
Longest span54 ft (16.6 m)
Deck width35 ft (10.7 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,200 (2022)
Projected traffic2,273 by 2046
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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 Rockton RD over Rock River Overflow built?

It was built in 1989, making it 36 years old in 2025.

What condition is Rockton RD over Rock River Overflow 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 Rockton RD over Rock River Overflow carry?

About 2,200 vehicles per day (2022 count), of which roughly 5% are trucks.

How long is Rockton RD over Rock River Overflow?

The structure is 219 ft (66.7 m) long with a longest span of 54 ft (16.6 m) and a deck 35 ft wide.

Who owns Rockton RD over Rock River Overflow?

It is owned by the County Highway Agency.