US Bridges

Il 97 over Spoon River

Fair

Knox County, Illinois · 1 MI SE of Maquon · Structure no. 048010000000000

Built
2015
10 years old
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
857 ft
7 main spans
Daily traffic
1,850
2023 count
Owner
State
State Highway Agency

About this bridge

Il 97 over Spoon River is a steel continuous stringer/multi-beam or girder carrying Il 97 over Spoon River in Knox County, Illinois. It was built in 2015, so it is 10 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 1,850 vehicles a day, roughly 18% of them trucks, projected to reach 1,818 by 2046. The structure is 857 ft (261.1 m) long and 35 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesIl 97
CrossesSpoon River
Location1 MI SE of Maquon
RouteState Highway 97
CountyKnox County
StateIllinois
Coordinates40.78454, -90.15415
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating52.1 US tons
Inventory rating40.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans7
Design loadHS 25 or greater
Structure length857 ft (261.1 m)
Longest span160 ft (48.8 m)
Deck width35 ft (10.7 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,850 (2023)
Projected traffic1,818 by 2046
Trucks18%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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 97 over Spoon River built?

It was built in 2015, making it 10 years old in 2025.

What condition is Il 97 over Spoon 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 July 2023.

How much traffic does Il 97 over Spoon River carry?

About 1,850 vehicles per day (2023 count), of which roughly 18% are trucks.

How long is Il 97 over Spoon River?

The structure is 857 ft (261.1 m) long with a longest span of 160 ft (48.8 m) and a deck 35 ft wide.

Who owns Il 97 over Spoon River?

It is owned by the State Highway Agency.