US Bridges

Il 171 (1st Ave) over Salt Creek

Good

Cook County, Illinois · 0.2 M N US 34 · Structure no. 016070200000000

Built
1931
94 years old, rebuilt 1984
Condition
Good
inspected August 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
114 ft
2 main spans
Daily traffic
36,500
2023 count
Owner
State
State Highway Agency

About this bridge

Il 171 (1st Ave) over Salt Creek is a prestressed concrete continuous stringer/multi-beam or girder carrying Il 171 (1st Ave) over Salt Creek in Cook County, Illinois. It was built in 1931 and reconstructed in 1984, so it is 94 years old, older than the Illinois average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 36,500 vehicles a day, roughly 7% of them trucks, projected to reach 36,865 by 2046. The structure is 114 ft (34.7 m) long and 60 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesIl 171 (1st Ave)
CrossesSalt Creek
Location0.2 M N US 34
RouteState Highway 171
CountyCook County
StateIllinois
Coordinates41.81839, -87.83346
Functional classUrban Other Principal Arterial

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating69.7 US tons
Inventory rating41.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length114 ft (34.7 m)
Longest span54 ft (16.5 m)
Deck width60 ft (18.2 m)
Roadway width46 ft (14 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic36,500 (2023)
Projected traffic36,865 by 2046
Trucks7%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$1.6 million
NavigationNo navigation control on waterway

Frequently asked questions

When was Il 171 (1st Ave) over Salt Creek built?

It was built in 1931, making it 94 years old in 2025. It was reconstructed in 1984.

What condition is Il 171 (1st Ave) over Salt Creek in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in August 2023.

How much traffic does Il 171 (1st Ave) over Salt Creek carry?

About 36,500 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is Il 171 (1st Ave) over Salt Creek?

The structure is 114 ft (34.7 m) long with a longest span of 54 ft (16.5 m) and a deck 60 ft wide.

Who owns Il 171 (1st Ave) over Salt Creek?

It is owned by the State Highway Agency.