US Bridges

Garden Prairie over Kishwaukee River

Fair

Boone County, Illinois · .5 MI N US 20 · Structure no. 004309700000000

Built
2015
10 years old
Condition
Fair
inspected March 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
204 ft
2 main spans
Daily traffic
2,850
2023 count
Owner
County
County Highway Agency

About this bridge

Garden Prairie over Kishwaukee River is a steel continuous stringer/multi-beam or girder carrying Garden Prairie over Kishwaukee River in Boone 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 2,850 vehicles a day, roughly 11% of them trucks, projected to reach 2,860 by 2046. The structure is 204 ft (62.2 m) long and 32 ft wide. If it were closed, the detour would be 14.3 mi (23 km).

Location

Open in Google Maps
CarriesGarden Prairie
CrossesKishwaukee River
Location.5 MI N US 20
RouteCounty Highway 0
CountyBoone County
StateIllinois
Coordinates42.26126, -88.7252
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.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
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 rating46.4 US tons
Inventory rating35.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 25 or greater
Structure length204 ft (62.2 m)
Longest span119 ft (36.2 m)
Deck width32 ft (9.8 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,850 (2023)
Projected traffic2,860 by 2046
Trucks11%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed14.3 mi (23 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 Garden Prairie over Kishwaukee River built?

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

What condition is Garden Prairie over Kishwaukee 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 March 2024.

How much traffic does Garden Prairie over Kishwaukee River carry?

About 2,850 vehicles per day (2023 count), of which roughly 11% are trucks.

How long is Garden Prairie over Kishwaukee River?

The structure is 204 ft (62.2 m) long with a longest span of 119 ft (36.2 m) and a deck 32 ft wide.

Who owns Garden Prairie over Kishwaukee River?

It is owned by the County Highway Agency.