IL 171
Carrying IL 171 over FIDDYMENT CREEK
3.8 M S OF COOK CO, Will, Illinois
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: IL 171
The IL 171 bridge in Will, Illinois carries IL 171 over FIDDYMENT CREEK. It was built in 1989, making it 37 years old today. The structure is built primarily of prestressed concrete and spans 1 section, stretching 26.3 meters (86 feet) end to end. Daily traffic averages 18,000 vehicles, placing it in the heavily-trafficked tier of Illinois bridges. It is owned and maintained by State Highway Agency.
The latest FHWA inspection records show a deck rating of 6/9, superstructure at 7/9, substructure at 8/9. The weakest component sits in fair condition. All reported major components score above the Poor range. Its NBI inventory load rating is 53.1 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How IL 171 compares
Live comparison across Illinois.
Historical Sufficiency Rating
PlainBridge-computedFHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Structural Details
- Year Built
- 1989
- Material
- Prestressed Concrete
- Number of Spans
- 1
- Structure Length
- 26.3 m (86 ft)
- Deck Width
- 25.0 m (82 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 18,000 vehicles/day
- Structure Number
- 099029200000000
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • At 6/9, the deck (driving surface) shows fair condition, with minor wear flagged for upkeep.
- • The superstructure (beams and supports above the deck) rates good at 7/9, with no significant deterioration on file.
- • The substructure (piers and abutments) is in good condition (8/9), showing no significant deterioration.
How to read this record
This page shows what the last federal inspection recorded, not whether IL 171 is safe to cross today. Here is how to use it.
- NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
- Learn how the 0–9 condition scale and Good/Fair/Poor categories are defined. How condition ratings work
- Compare IL 171 against other structures in Will and across Illinois. Illinois bridges
- Noticed visible damage or a safety concern? Report it to the agency that owns the bridge, or call 911 in an emergency. How to report a bridge
Condition codes come straight from the FHWA National Bridge Inventory and are not a real-time safety judgment. Only the owning agency, a state DOT, county, or other owner, can post, restrict, or close a bridge.
Frequently Asked Questions
What do the condition ratings mean for IL 171?
IL 171 in Will, Illinois has a deck rating of 6/9, superstructure rating of 7/9, and substructure rating of 8/9 on the FHWA's 0–9 scale.
How often is IL 171 inspected?
IL 171's responsible agency sets its routine interval under FHWA's risk-based inspection rules; this page does not expose the scheduled interval. It carries about 18,000 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. IL 171 is currently shown as Fair condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for IL 171?
IL 171 has an NBI inventory load rating of 53.1 metric tons.
Who is responsible for maintaining IL 171?
IL 171 is owned and maintained by State Highway Agency.
How old is IL 171 and does age affect safety?
IL 171 was built in 1989, making it 37 years old.
Disclaimer: Bridge condition data is from the FHWA NBI and reflects the last reported inspection. A Poor condition rating is not a live declaration that a bridge is closed or unsafe for travel. For current closure, posting, or safety information, contact the responsible transportation agency.
Every figure on PlainBridge is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.