TR 6A,MERCER CO LI
Carrying TR 6A,MERCER CO LI over TRIB.TO N.HENDERSON
SW-7-T13NR1E, Knox, Illinois
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: TR 6A,MERCER CO LI
The TR 6A,MERCER CO LI bridge in Knox, Illinois carries TR 6A,MERCER CO LI over TRIB.TO N.HENDERSON. It was built in 1965, making it 61 years old today. The structure is built primarily of prestressed concrete and spans 1 section, stretching 10.2 meters (33 feet) end to end. Daily traffic averages 10 vehicles, placing it in the lower-traffic tier of Illinois bridges. It is owned and maintained by Town/Township Highway Agency.
The latest FHWA inspection records show a deck rating of 6/9, superstructure at 6/9, substructure at 4/9. The weakest component sits in poor condition. A component scored 4 or below, placing this bridge in the federal Poor condition category rather than declaring it unsafe or closed. Its NBI inventory load rating is 27.9 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How TR 6A,MERCER CO LI 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 How the historical reference is calculated.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
- 1965
- Material
- Prestressed Concrete
- Number of Spans
- 1
- Structure Length
- 10.2 m (33 ft)
- Deck Width
- 6.8 m (22 ft)
- Owner
- Town/Township Highway Agency
- Avg Daily Traffic
- 10 vehicles/day
- Structure Number
- 048305300000000
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The deck (driving surface) rates fair at 6/9, minor deterioration that routine maintenance should address.
- • The superstructure (beams and supports above the deck) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
- • At 4/9, the substructure (piers and abutments) is in poor shape, with advanced wear flagged for priority repair.
How to read this record
TR 6A,MERCER CO LI is in the federal Poor condition category. That is a component-based result, not a closure order.
- NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
- Understand what Poor condition does and does not mean before drawing conclusions. Poor condition explained
- Compare TR 6A,MERCER CO LI against other structures in Knox 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 TR 6A,MERCER CO LI?
TR 6A,MERCER CO LI in Knox, Illinois has a deck rating of 6/9, superstructure rating of 6/9, and substructure rating of 4/9 on the FHWA's 0–9 scale.
How often is TR 6A,MERCER CO LI inspected?
TR 6A,MERCER CO LI'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 10 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. TR 6A,MERCER CO LI is currently shown as Poor condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for TR 6A,MERCER CO LI?
TR 6A,MERCER CO LI has an NBI inventory load rating of 27.9 metric tons.
Who is responsible for maintaining TR 6A,MERCER CO LI?
TR 6A,MERCER CO LI is owned and maintained by Town/Township Highway Agency.
How old is TR 6A,MERCER CO LI and does age affect safety?
TR 6A,MERCER CO LI was built in 1965, making it 61 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.