US Bridges

US 20 WB over I-90

Fair

Boone County, Illinois · .13 MI E Wheeler RD · Structure no. 004990000000000

Built
1958
67 years old, rebuilt 1993
Condition
Fair
inspected June 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
320 ft
4 main spans
Daily traffic
14,200
2023 count
Owner
State
State Highway Agency

About this bridge

US 20 WB over I-90 is a steel continuous stringer/multi-beam or girder carrying US 20 WB over I-90 in Boone County, Illinois. It was built in 1958 and reconstructed in 1993, so it is 67 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 14,200 vehicles a day, roughly 11% of them trucks, projected to reach 7,176 by 2046. The structure is 320 ft (97.5 m) long and 37 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesUS 20 WB
CrossesI-90
Location.13 MI E Wheeler RD
RouteU.S. Route 20
CountyBoone County
StateIllinois
Coordinates42.23954, -88.91762
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
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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
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
Approach roadway alignment8: Equal to present desirable criteria
Operating rating88.6 US tons
Inventory rating53.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20 + Mod
Structure length320 ft (97.5 m)
Longest span94 ft (28.7 m)
Deck width37 ft (11.3 m)
Roadway width34 ft (10.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic14,200 (2023)
Projected traffic7,176 by 2046
Trucks11%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was US 20 WB over I-90 built?

It was built in 1958, making it 67 years old in 2025. It was reconstructed in 1993.

What condition is US 20 WB over I-90 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 June 2023.

How much traffic does US 20 WB over I-90 carry?

About 14,200 vehicles per day (2023 count), of which roughly 11% are trucks.

How long is US 20 WB over I-90?

The structure is 320 ft (97.5 m) long with a longest span of 94 ft (28.7 m) and a deck 37 ft wide.

Who owns US 20 WB over I-90?

It is owned by the State Highway Agency.