NW 170 Ave
Carrying NW 170 Ave over GENE CREEK
6.5W 1.0N OF ATTICA, Harper, Kansas
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
NW 170 Ave in Harper, Kansas sits above 24% of rated Kansas bridges on inventory load rating (19 t), while its 1948 build year is earlier than 67% of Harper's recorded-year cohort (372 bridges).
NW 170 Ave in Harper, Kansas is rated Poor in the FHWA's 2024 National Bridge Inventory. Built in 1948, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 4. The lowest applicable rating sets the federal condition category, so this Poor 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:000390709006763
PRE-1950 · TIMBER · MULTI-SPAN · SUB-LED · TRACE-ADT · LIGHT-LOAD · CAT-POOR
- PRE-1950 Pre-1950
- TIMBER Wood or timber
- MULTI-SPAN 2 spans
- SUB-LED Substructure-led
- TRACE-ADT Trace ADT
- LIGHT-LOAD Light load
- CAT-POOR Poor
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: NW 170 Ave
The NW 170 Ave bridge in Harper, Kansas carries NW 170 Ave over GENE CREEK. It was built in 1948, making it 78 years old today. The structure is built primarily of wood or timber and spans 2 sections, stretching 10.7 meters (35 feet) end to end. Daily traffic averages 20 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 4/9. The weakest component sits in poor condition. Because at least one major component scores 4 or lower, this bridge falls in FHWA's Poor condition category. That category is not a closure order.
How NW 170 Ave compares
Age against the county: built in 1948, earlier than 250 of Harper's 372 bridges with a recorded construction year (67%), against a county median build year of 1965. 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).
NW 170 Ave vs every rated Kansas bridge
Inventory load rating (metric tons), FHWA NBI, this state
19 Top 76% higher than 24% 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.
Harper inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 372 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
- 1948
- Material
- Wood or Timber
- Number of Spans
- 2
- Structure Length
- 10.7 m (35 ft)
- Deck Width
- 6.2 m (20 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 20 vehicles/day
- Structure Number
- 000390709006763
Condition Analysis
- • The deck (driving surface) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
- • At 6/9, the superstructure (beams and supports above the deck) shows fair condition, with minor wear flagged for upkeep.
- • At 4/9, the substructure (piers and abutments) is in poor shape, with advanced wear on file for this vintage.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
NW 170 Ave 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 NW 170 Ave against other structures in Harper 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 NW 170 Ave?
NW 170 Ave in Harper, Kansas 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 NW 170 Ave inspected?
NW 170 Ave'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 20 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. NW 170 Ave 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 NW 170 Ave?
NW 170 Ave has an NBI inventory load rating of 18.6 metric tons.
Who is responsible for maintaining NW 170 Ave?
NW 170 Ave is owned and maintained by County Highway Agency.
How old is NW 170 Ave and does age affect safety?
NW 170 Ave was built in 1948, making it 78 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.