US Bridges

I- 55 NB over Des Plaines River

Fair

Will County, Illinois · 2.3 M S of US 6 · Structure no. 099000900000000

Built
1957
68 years old, rebuilt 2002
Condition
Fair
inspected August 2023
Type
Truss - Thru
Steel Continuous
Length
1,406 ft
3 main spans
Daily traffic
31,250
2024 count
Owner
State
State Highway Agency

About this bridge

I- 55 NB over Des Plaines River is a steel continuous truss - thru carrying I- 55 NB over Des Plaines River in Will County, Illinois. It was built in 1957 and reconstructed in 2002, so it is 68 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 31,250 vehicles a day, roughly 5% of them trucks, projected to reach 36,936 by 2046. The structure is 1,406 ft (428.5 m) long and 36 ft wide. If it were closed, the detour would be 24.9 mi (40 km).

Location

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CarriesI- 55 NB
CrossesDes Plaines River
Location2.3 M S of US 6
RouteInterstate 55
CountyWill County
StateIllinois
Coordinates41.42004, -88.19436
Functional classUrban Principal Arterial - Interstate

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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2023
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 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 rating54.7 US tons
Inventory rating32.8 US tons

Structure

Structure typeTruss - Thru
MaterialSteel Continuous
DeckClosed grating
Main spans3 (+4 approach)
Design loadUnknown
Structure length1,406 ft (428.5 m)
Longest span486 ft (148.1 m)
Deck width36 ft (10.9 m)
Roadway width32 ft (9.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic31,250 (2024)
Projected traffic36,936 by 2046
Trucks5%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed24.9 mi (40 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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—
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was I- 55 NB over Des Plaines River built?

It was built in 1957, making it 68 years old in 2025. It was reconstructed in 2002.

What condition is I- 55 NB over Des Plaines 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 August 2023.

How much traffic does I- 55 NB over Des Plaines River carry?

About 31,250 vehicles per day (2024 count), of which roughly 5% are trucks.

How long is I- 55 NB over Des Plaines River?

The structure is 1,406 ft (428.5 m) long with a longest span of 486 ft (148.1 m) and a deck 36 ft wide.

Who owns I- 55 NB over Des Plaines River?

It is owned by the State Highway Agency.