TR 105
Carrying TR 105 over PARKER RUN
SW-27-T15NR1W, Mercer, Illinois
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
TR 105 in Mercer, Illinois sits above 62% of rated Illinois bridges on inventory load rating (33 t), while its 1975 build year is earlier than 71% of Mercer's recorded-year cohort (163 bridges).
TR 105 in Mercer, Illinois is rated Fair in the FHWA's 2024 National Bridge Inventory. Built in 1975, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 6. The lowest applicable rating sets the federal condition category, so this Fair 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:066511000000000
INTERSTATE-ERA · STEEL · SINGLE-SPAN · DECK-LED · LOCAL-ADT · STANDARD-LOAD · CAT-FAIR
- INTERSTATE-ERA 1950–1979
- STEEL Steel
- SINGLE-SPAN Single span
- DECK-LED Deck-led
- LOCAL-ADT Local ADT
- STANDARD-LOAD Standard load
- CAT-FAIR Fair
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: TR 105
The TR 105 bridge in Mercer, Illinois carries TR 105 over PARKER RUN. It was built in 1975, making it 51 years old today. The structure is built primarily of steel and spans 1 section, stretching 15.2 meters (50 feet) end to end. Daily traffic averages 75 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 7/9, substructure at 7/9. The weakest component sits in fair condition. All reported major components score above the Poor range.
How TR 105 compares
Age against the county: built in 1975, earlier than 115 of Mercer's 163 bridges with a recorded construction year (71%), against a county median build year of 1984. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.
Live comparison across Illinois bridges with a recorded inventory load rating (26,904 of 26,928 rated).
TR 105 vs every rated Illinois bridge
Inventory load rating (metric tons), FHWA NBI, this state
33 Top 38% higher than 62% 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.
Mercer inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 163 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
- 1975
- Material
- Steel
- Number of Spans
- 1
- Structure Length
- 15.2 m (50 ft)
- Deck Width
- 6.1 m (20 ft)
- Owner
- Town/Township Highway Agency
- Avg Daily Traffic
- 75 vehicles/day
- Structure Number
- 066511000000000
Condition Analysis
- • The deck (driving surface) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
- • At 7/9, the superstructure (beams and supports above the deck) is in good shape and shows no significant wear.
- • The substructure (piers and abutments) rates good at 7/9, with no significant deterioration on file.
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 TR 105 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 TR 105 against other structures in Mercer 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 105?
TR 105 in Mercer, Illinois has a deck rating of 6/9, superstructure rating of 7/9, and substructure rating of 7/9 on the FHWA's 0–9 scale.
How often is TR 105 inspected?
TR 105'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 75 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. TR 105 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 TR 105?
TR 105 has an NBI inventory load rating of 33.0 metric tons.
Who is responsible for maintaining TR 105?
TR 105 is owned and maintained by Town/Township Highway Agency.
How old is TR 105 and does age affect safety?
TR 105 was built in 1975, making it 51 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.