US Bridges

I-90 Skyway over Conrail RR

Fair

Cook County, Illinois · 0.19 M NW 100th · Structure no. 016642100000000

Built
1958
67 years old, rebuilt 2003
Condition
Fair
inspected September 2023
Type
Truss - Deck
Steel Continuous
Length
405 ft
3 main spans
Daily traffic
28,700
2020 count
Owner
City
City or Municipal Highway Agency

About this bridge

I-90 Skyway over Conrail RR is a steel continuous truss - deck carrying I-90 Skyway over Conrail RR in Cook County, Illinois. It was built in 1958 and reconstructed in 2003, 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 28,700 vehicles a day, roughly 16% of them trucks, projected to reach 28,987 by 2046. The structure is 405 ft (123.4 m) long and 83 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesI-90 Skyway
CrossesConrail RR
Location0.19 M NW 100th
RouteInterstate 90
CountyCook County
StateIllinois
Coordinates41.71476, -87.53787
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.
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 inspectionSeptember 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 geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating65 US tons
Inventory rating38.9 US tons

Structure

Structure typeTruss - Deck
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length405 ft (123.4 m)
Longest span155 ft (47.3 m)
Deck width83 ft (25.3 m)
Roadway width77 ft (23.6 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
CrossesRailroad
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$5.3 million
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-90 Skyway over Conrail RR built?

It was built in 1958, making it 67 years old in 2025. It was reconstructed in 2003.

What condition is I-90 Skyway over Conrail RR 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 September 2023.

How much traffic does I-90 Skyway over Conrail RR carry?

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

How long is I-90 Skyway over Conrail RR?

The structure is 405 ft (123.4 m) long with a longest span of 155 ft (47.3 m) and a deck 83 ft wide.

Who owns I-90 Skyway over Conrail RR?

It is owned by the City or Municipal Highway Agency.