US Bridges

Il 171 NB to I-55 over San & Ship Canal

Fair

Cook County, Illinois · 1 M N Archer Ave · Structure no. 016240800000000

Built
1981
44 years old, rebuilt 2001
Condition
Fair
inspected November 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
635 ft
5 main spans
Daily traffic
14,500
2023 count
Owner
State
State Highway Agency

About this bridge

Il 171 NB to I-55 over San & Ship Canal is a steel continuous stringer/multi-beam or girder carrying Il 171 NB to I-55 over San & Ship Canal in Cook County, Illinois. It was built in 1981 and reconstructed in 2001, so it is 44 years old, younger 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 14,500 vehicles a day, roughly 5% of them trucks, projected to reach 4,697 by 2046. The structure is 635 ft (193.6 m) long and 28 ft wide.

Location

Open in Google Maps
CarriesIl 171 NB to I-55
CrossesSan & Ship Canal
Location1 M N Archer Ave
CountyCook County
StateIllinois
Coordinates41.79187, -87.81577
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.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionNovember 2024
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 geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating91.1 US tons
Inventory rating54.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20
Structure length635 ft (193.6 m)
Longest span188 ft (57.4 m)
Deck width28 ft (8.5 m)
Roadway width25 ft (7.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic14,500 (2023)
Projected traffic4,697 by 2046
Trucks5%
Lanes on structure1
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
CrossesWaterway
Detour if closed—
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—
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was Il 171 NB to I-55 over San & Ship Canal built?

It was built in 1981, making it 44 years old in 2025. It was reconstructed in 2001.

What condition is Il 171 NB to I-55 over San & Ship Canal 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 November 2024.

How much traffic does Il 171 NB to I-55 over San & Ship Canal carry?

About 14,500 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is Il 171 NB to I-55 over San & Ship Canal?

The structure is 635 ft (193.6 m) long with a longest span of 188 ft (57.4 m) and a deck 28 ft wide.

Who owns Il 171 NB to I-55 over San & Ship Canal?

It is owned by the State Highway Agency.