US Bridges

Whitman ST over Rock River

Fair

Winnebago County, Illinois · 0.03 MI W of N Main · Structure no. 101613600000000

Built
1960
65 years old, rebuilt 2000
Condition
Fair
inspected October 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
742 ft
7 main spans
Daily traffic
19,400
2022 count
Owner
City
City or Municipal Highway Agency

About this bridge

Whitman ST over Rock River is a steel stringer/multi-beam or girder carrying Whitman ST over Rock River in Winnebago County, Illinois. It was built in 1960 and reconstructed in 2000, so it is 65 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 19,400 vehicles a day, roughly 4% of them trucks, projected to reach 21,614 by 2046. The structure is 742 ft (226.2 m) long and 71 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesWhitman ST
CrossesRock River
Location0.03 MI W of N Main
CountyWinnebago County
StateIllinois
Coordinates42.27831, -89.08636
Functional classUrban Other Principal 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
Deck7 GoodSome minor problems.
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 protection7 GoodSome minor problems.
Last inspectionOctober 2023
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 geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating71.8 US tons
Inventory rating42.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans7
Design loadHS 20
Structure length742 ft (226.2 m)
Longest span141 ft (43 m)
Deck width71 ft (21.6 m)
Roadway width54 ft (16.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic19,400 (2022)
Projected traffic21,614 by 2046
Trucks4%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedWidening with deck rehabilitation or replacement
Estimated improvement cost$3.3 million
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was Whitman ST over Rock River built?

It was built in 1960, making it 65 years old in 2025. It was reconstructed in 2000.

What condition is Whitman ST over Rock River 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 2023.

How much traffic does Whitman ST over Rock River carry?

About 19,400 vehicles per day (2022 count), of which roughly 4% are trucks.

How long is Whitman ST over Rock River?

The structure is 742 ft (226.2 m) long with a longest span of 141 ft (43 m) and a deck 71 ft wide.

Who owns Whitman ST over Rock River?

It is owned by the City or Municipal Highway Agency.