RD 170 931.5-520
Carrying RD 170 931.5-520 over LINDY CREEK
0.5S 2.0E OF PLYMOUTH, Lyon, Kansas
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
RD 170 931.5-520 in Lyon, Kansas sits above 50% of rated Kansas bridges on inventory load rating (28 t), while its 1921 build year is earlier than 99% of Lyon's recorded-year cohort (492 bridges).
RD 170 931.5-520 in Lyon, Kansas is rated Fair in the FHWA's 2024 National Bridge Inventory. Built in 1921, 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 KS:000560931505200
PRE-1950 · CONCRETE · SINGLE-SPAN · TIED-CTRL · LOCAL-ADT · STANDARD-LOAD · CAT-FAIR
- PRE-1950 Pre-1950
- CONCRETE Concrete
- SINGLE-SPAN Single span
- TIED-CTRL Tied control
- 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: RD 170 931.5-520
The RD 170 931.5-520 bridge in Lyon, Kansas carries RD 170 931.5-520 over LINDY CREEK. It was built in 1921, making it 105 years old today. The structure is built primarily of concrete and spans 1 section, stretching 14.2 meters (47 feet) end to end. Daily traffic averages 50 vehicles, placing it in the lower-traffic tier of Kansas bridges. It is owned and maintained by County Highway Agency.
The latest FHWA inspection records show a deck rating of 6/9, superstructure at 6/9, substructure at 6/9. The weakest component sits in fair condition. All reported major components score above the Poor range.
How RD 170 931.5-520 compares
Age against the county: built in 1921, earlier than 488 of Lyon's 492 bridges with a recorded construction year (99%), against a county median build year of 1974. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.
Live comparison across Kansas bridges with a recorded inventory load rating (24,893 of 24,894 rated).
RD 170 931.5-520 vs every rated Kansas bridge
Inventory load rating (metric tons), FHWA NBI, this state
28 Top 50% higher than 50% of 24,893 bridges
rated Kansas 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.
Lyon inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 492 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
- 1921
- Material
- Concrete
- Number of Spans
- 1
- Structure Length
- 14.2 m (47 ft)
- Deck Width
- 6.9 m (23 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 50 vehicles/day
- Structure Number
- 000560931505200
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.
- • The substructure (piers and abutments) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
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 RD 170 931.5-520 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 RD 170 931.5-520 against other structures in Lyon and across Kansas. Kansas 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 RD 170 931.5-520?
RD 170 931.5-520 in Lyon, Kansas has a deck rating of 6/9, superstructure rating of 6/9, and substructure rating of 6/9 on the FHWA's 0–9 scale.
How often is RD 170 931.5-520 inspected?
RD 170 931.5-520'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 50 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. RD 170 931.5-520 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 RD 170 931.5-520?
RD 170 931.5-520 has an NBI inventory load rating of 27.9 metric tons.
Who is responsible for maintaining RD 170 931.5-520?
RD 170 931.5-520 is owned and maintained by County Highway Agency.
How old is RD 170 931.5-520 and does age affect safety?
RD 170 931.5-520 was built in 1921, making it 105 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.