US Bridges

I-90 Skyway over ST Lawrence Ave

Fair

Cook County, Illinois · At 70th P7C · Structure no. 016630100000000

Built
1958
67 years old, rebuilt 1994
Condition
Fair
inspected August 2022
Type
Stringer/Multi-beam or Girder
Steel
Length
134 ft
1 main span
Daily traffic
28,700
2020 count
Owner
City
City or Municipal Highway Agency

About this bridge

I-90 Skyway over ST Lawrence Ave is a steel stringer/multi-beam or girder carrying I-90 Skyway over ST Lawrence Ave in Cook County, Illinois. It was built in 1958 and reconstructed in 1994, 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 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 28,700 vehicles a day, roughly 16% of them trucks, projected to reach 28,987 by 2046. The structure is 134 ft (40.8 m) long and 110 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

CarriesI-90 Skyway
CrossesST Lawrence Ave
LocationAt 70th P7C
RouteInterstate 90
Coordinates41.76789, -87.61107
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2022
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating107.1 US tons
Inventory rating65.7 US tons

Structure

MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length134 ft (40.8 m)
Longest span126 ft (38.3 m)
Deck width110 ft (33.5 m)
Roadway width104 ft (31.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic28,700 (2020)
Projected traffic28,987 by 2046
Trucks16%
Lanes on structure6
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.9 mi (3 km)
TollOn a toll road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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 proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-90 Skyway over ST Lawrence Ave built?

It was built in 1958, making it 67 years old in 2025. It was reconstructed in 1994.

What condition is I-90 Skyway over ST Lawrence Ave 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 2022.

How much traffic does I-90 Skyway over ST Lawrence Ave carry?

About 28,700 vehicles per day (2020 count), of which roughly 16% are trucks.

How long is I-90 Skyway over ST Lawrence Ave?

The structure is 134 ft (40.8 m) long with a longest span of 126 ft (38.3 m) and a deck 110 ft wide.

Who owns I-90 Skyway over ST Lawrence Ave?

It is owned by the City or Municipal Highway Agency.