US Bridges

Rock City RD over Rock Run CR

Fair

Stephenson County, Illinois · 3.0 MI W Davis · Structure no. 089300200000000

Built
1965
60 years old
Condition
Fair
inspected October 2024
Type
Slab
Concrete Continuous
Length
101 ft
3 main spans
Daily traffic
725
2024 count
Owner
County
County Highway Agency

About this bridge

Rock City RD over Rock Run CR is a concrete continuous slab carrying Rock City RD over Rock Run CR in Stephenson County, Illinois. It was built in 1965, so it is 60 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 725 vehicles a day, roughly 7% of them trucks, projected to reach 631 by 2046. The structure is 101 ft (30.7 m) long and 30 ft wide. If it were closed, the detour would be 13 mi (21 km).

Location

Open in Google Maps
CarriesRock City RD
CrossesRock Run CR
Location3.0 MI W Davis
RouteCounty Highway 0
CountyStephenson County
StateIllinois
Coordinates42.42823, -89.4774
Functional classRural Major 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
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.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
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 adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating53.2 US tons
Inventory rating31.7 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 15
Structure length101 ft (30.7 m)
Longest span36 ft (11.1 m)
Deck width30 ft (9.2 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic725 (2024)
Projected traffic631 by 2046
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed13 mi (21 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 Rock City RD over Rock Run CR built?

It was built in 1965, making it 60 years old in 2025.

What condition is Rock City RD over Rock Run CR 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 October 2024.

How much traffic does Rock City RD over Rock Run CR carry?

About 725 vehicles per day (2024 count), of which roughly 7% are trucks.

How long is Rock City RD over Rock Run CR?

The structure is 101 ft (30.7 m) long with a longest span of 36 ft (11.1 m) and a deck 30 ft wide.

Who owns Rock City RD over Rock Run CR?

It is owned by the County Highway Agency.