US Bridges

Il 171 (1st Ave) over Silver Creek

Fair

Cook County, Illinois · 0.6 M N Lake ST · Structure no. 016069800000000

Built
1934
91 years old, rebuilt 1989
Condition
Fair
inspected June 2024
Type
Tee Beam
Concrete
Length
33 ft
1 main span
Daily traffic
27,400
2023 count
Owner
State
State Highway Agency

About this bridge

Il 171 (1st Ave) over Silver Creek is a concrete tee beam carrying Il 171 (1st Ave) over Silver Creek in Cook County, Illinois. It was built in 1934 and reconstructed in 1989, so it is 91 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 27,400 vehicles a day, roughly 6% of them trucks, projected to reach 25,048 by 2046. The structure is 33 ft (10.1 m) long and 60 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesIl 171 (1st Ave)
CrossesSilver Creek
Location0.6 M N Lake ST
RouteState Highway 171
CountyCook County
StateIllinois
Coordinates41.89804, -87.83521
Functional classUrban Other Principal Arterial

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.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to 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 rating66 US tons
Inventory rating39.7 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length33 ft (10.1 m)
Longest span31 ft (9.4 m)
Deck width60 ft (18.3 m)
Roadway width48 ft (14.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic27,400 (2023)
Projected traffic25,048 by 2046
Trucks6%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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$456,000
NavigationNo navigation control on waterway

Frequently asked questions

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

It was built in 1934, making it 91 years old in 2025. It was reconstructed in 1989.

What condition is Il 171 (1st Ave) over Silver Creek 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 June 2024.

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

About 27,400 vehicles per day (2023 count), of which roughly 6% are trucks.

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

The structure is 33 ft (10.1 m) long with a longest span of 31 ft (9.4 m) and a deck 60 ft wide.

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

It is owned by the State Highway Agency.