IL 21
Carrying IL 21 over IL 120 & STREAM
1 M W OF I-94, Lake, Illinois
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
IL 21 in Lake, Illinois sits above 72% of rated Illinois bridges on inventory load rating (37 t), while its 2003 build year is earlier than 21% of Lake's recorded-year cohort (251 bridges).
IL 21 in Lake, Illinois is rated Good in the FHWA's 2024 National Bridge Inventory. Built in 2003, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 7. The lowest applicable rating sets the federal condition category, so this Good result describes the weakest reported component rather than the structure as a whole. No NBI category is a closure decision or a live crossing-safety verdict.
NBI record plate
Structure IL:049017900000000
POST-2000 · STEEL · MULTI-SPAN · TIED-CTRL · HEAVY-ADT · STANDARD-LOAD · CAT-GOOD
- POST-2000 2000+
- STEEL Steel
- MULTI-SPAN 2 spans
- TIED-CTRL Tied control
- HEAVY-ADT Heavy ADT
- STANDARD-LOAD Standard load
- CAT-GOOD Good
Inspection-sheet codes from this record’s year, material family, spans, controlling component, ADT, inventory load, and NBI category, not a live closure verdict.
Bridge Snapshot: IL 21
The IL 21 bridge in Lake, Illinois carries IL 21 over IL 120 & STREAM. It was built in 2003, making it 23 years old today. The structure is built primarily of steel continuous and spans 2 sections, stretching 164.0 meters (538 feet) end to end. Daily traffic averages 22,300 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 7/9, superstructure at 7/9, substructure at 7/9. The weakest component sits in good condition. All reported major components score above the Poor range.
How IL 21 compares
Age against the county: built in 2003, earlier than 52 of Lake's 251 bridges with a recorded construction year (21%), against a county median build year of 1977. This is one of the newer structures in its county.
Live comparison across Illinois bridges with a recorded inventory load rating (26,904 of 26,928 rated).
IL 21 vs every rated Illinois bridge
Inventory load rating (metric tons), FHWA NBI, this state
37 Top 28% higher than 72% of 26,904 bridges
rated Illinois bridges, bucketed by value
Each bar is a band; taller bars hold more bridges. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source FHWA National Bridge Inventory · August 2026
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Reported 0–9 component ratings from the FHWA NBI. The highlighted component is the lowest reported input to this record’s current condition category; it is not a closure or live crossing-safety decision.
Lake inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 251 bridges in this county. Orthogonal to this structure's component profile above: a county catalog share, not a live crossing-safety verdict.
Structural Details
- Year Built
- 2003
- Material
- Steel Continuous
- Number of Spans
- 2
- Structure Length
- 164.0 m (538 ft)
- Deck Width
- 24.3 m (80 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 22,300 vehicles/day
- Structure Number
- 049017900000000
Condition Analysis
- • The deck (driving surface) is in good condition (7/9), showing no significant deterioration.
- • The superstructure (beams and supports above the deck) is in good condition (7/9), showing no significant deterioration.
- • The substructure (piers and abutments) is in good condition (7/9), showing no significant deterioration.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
This page shows what the last federal inspection recorded, not whether IL 21 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 21 against other structures in Lake 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 21?
IL 21 in Lake, Illinois has a deck rating of 7/9, superstructure rating of 7/9, and substructure rating of 7/9 on the FHWA's 0–9 scale.
How often is IL 21 inspected?
IL 21'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 22,300 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. IL 21 is currently shown as Good condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for IL 21?
IL 21 has an NBI inventory load rating of 37.3 metric tons.
Who is responsible for maintaining IL 21?
IL 21 is owned and maintained by State Highway Agency.
How old is IL 21 and does age affect safety?
IL 21 was built in 2003, making it 23 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.
Share this inspection record
Send this source-bounded record or download its data card. An NBI condition category is not a closure or live crossing-safety verdict.
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. Component ratings, ADT, and condition category on this page are copied from the NBI record for this structure; no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2024 NBI release. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.