US Bridges

I-90 Skyway over 79th ST

Fair

Cook County, Illinois · 0.1 M W of Stony Isl · Structure no. 016645100000000

Built
1958
67 years old, rebuilt 2002
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
122 ft
1 main span
Daily traffic
28,700
2020 count
Owner
City
City or Municipal Highway Agency

About this bridge

I-90 Skyway over 79th ST is a steel stringer/multi-beam or girder carrying I-90 Skyway over 79th ST in Cook County, Illinois. It was built in 1958 and reconstructed in 2002, 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 122 ft (37.3 m) long and 107 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesI-90 Skyway
Crosses79th ST
Location0.1 M W of Stony Isl
RouteInterstate 90
CountyCook County
StateIllinois
Coordinates41.75129, -87.58799
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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2023
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 rating81 US tons
Inventory rating48.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length122 ft (37.3 m)
Longest span117 ft (35.8 m)
Deck width107 ft (32.7 m)
Roadway width101 ft (30.7 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 closed5 mi (8 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$1.6 million
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-90 Skyway over 79th ST built?

It was built in 1958, making it 67 years old in 2025. It was reconstructed in 2002.

What condition is I-90 Skyway over 79th ST 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-90 Skyway over 79th ST carry?

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

How long is I-90 Skyway over 79th ST?

The structure is 122 ft (37.3 m) long with a longest span of 117 ft (35.8 m) and a deck 107 ft wide.

Who owns I-90 Skyway over 79th ST?

It is owned by the City or Municipal Highway Agency.