Il 171 NB over Des Plaines River
FairCook County, Illinois · 0.2 M NW I-55 · Structure no. 016098500000000
- Built
- 1964
- 61 years old, rebuilt 2016
- Condition
- Fair
- inspected February 2023
- Type
- Stringer/Multi-beam or Girder
- Steel Continuous
- Length
- 528 ft
- 4 main spans
- Daily traffic
- 40,100
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
Il 171 NB over Des Plaines River is a steel continuous stringer/multi-beam or girder carrying Il 171 NB over Des Plaines River in Cook County, Illinois. It was built in 1964 and reconstructed in 2016, so it is 61 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 40,100 vehicles a day, roughly 9% of them trucks, projected to reach 19,443 by 2046. The structure is 528 ft (160.9 m) long and 43 ft wide. If it were closed, the detour would be 5 mi (8 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| Superstructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Il 171 NB over Des Plaines River built?
It was built in 1964, making it 61 years old in 2025. It was reconstructed in 2016.
What condition is Il 171 NB over Des Plaines River 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 February 2023.
How much traffic does Il 171 NB over Des Plaines River carry?
About 40,100 vehicles per day (2023 count), of which roughly 9% are trucks.
How long is Il 171 NB over Des Plaines River?
The structure is 528 ft (160.9 m) long with a longest span of 146 ft (44.5 m) and a deck 43 ft wide.
Who owns Il 171 NB over Des Plaines River?
It is owned by the State Highway Agency.