Total bridges
492
Public highway bridges in Lyon County
County profile · official public datasets
Lyon County, KS
492 public highway bridges tracked in the FHWA National Bridge Inventory: 65.7% rated Good, 33.3% Fair, 1% Poor.
- 492
- Public bridges
- 65.7%
- Good condition
- 1%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Lyon County posts a top-quartile lowest Poor-condition share among rated counties in the state across mid-size county bridge inventory.
- Top 18%
- lowest Poor share in state
- 1%
- Poor-condition share
- 492
- public highway bridges
- 1972
- avg year built
Poor is an FHWA condition category from the lowest applicable component rating (4 or below), not a live crossing-safety or closure decision. Rankings cover counties with at least five public highway bridges.
Lyon County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Lyon County ranks #19 of 104 Kansas counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 1%). Lyon County, Kansas contains 492 public highway bridges. Roughly 65.7% are rated “Good,” 33.3% “Fair,” and 1% “Poor.” Poor means the lowest applicable deck, superstructure, substructure, or culvert rating is 4 or below on the 0–9 NBI scale. It is a condition category, not a live safety or closure decision.
Responsible agencies inspect covered bridges on risk-based intervals under current NBIS rules and submit inventory data to FHWA annually. The list below shows every NBI-tracked bridge in the county. Use the “Sort by” controls to change the ordering, and click any row for its reported inspection date, traffic count, and condition fields.
Source: FHWA National Bridge Inventory. See methodology for full definitions.
Good condition
65.7%
323 of 492 rated 7-9
Fair condition
33.3%
164 of 492 rated 5-6
Poor condition
1%
5 of 492 rated 4 or below
In-state Poor-share rank
#19 of 104
Among Kansas counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 492 NBI-tracked bridges by lowest applicable component rating.
Good 65.7% (323)
Fair 33.3% (164)
Poor 1% (5)
Lyon County's Poor-condition bridges carry 225 vehicle crossings a day
That is 0% of the county's reported daily bridge traffic on 1% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 45 crossings a day against 1,414 for a Good-condition one. A Poor rating is a condition category, not a closure or a live safety judgement; it means the lowest applicable component rating is 4 or below.
Computed over the 492 of 492 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
50.2% of Lyon County's bridges have passed the 50-year mark
247 of the 492 bridges with a recorded construction year were built in 1974 or earlier. Age alone is not a defect: a well-maintained older bridge can rate Good, and 65.7% of this county's inventory does. Even so, this older cohort is the population from which future Poor ratings are drawn, which is why the age profile below matters alongside the condition split above.
Cutoff derives from the 2024 release year minus a 50-year design life. Source: FHWA National Bridge Inventory, 2024 release.
One structure carries 35.6% of the county's Poor-condition bridge traffic
RD H 939.0-544.1 over MOON BRANCH CREEK, built 1928, carries 80 vehicles a day, the most of any Poor-rated structure here. The county's Poor-condition exposure is concentrated rather than evenly spread, so the 5-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 225 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Lyon County's bridges were built
492 bridges with a recorded construction year, grouped by decade
- 1900s 1
1900–1909
1 bridges
- 1910s 2
1910–1919
2 bridges
- 1920s 25
1920–1929
25 bridges
- 1930s
1930–1939
48 bridges
- 1940s 34
1940–1949
34 bridges
- 1950s
1950–1959
89 bridges
- 1960s 34
1960–1969
34 bridges
- 1970s
1970–1979
46 bridges
- 1980s
1980–1989
51 bridges
- 1990s
1990–1999
56 bridges
- 2000s
2000–2009
58 bridges
- 2010s
2010–2019
42 bridges
- 2020s 6
2020–2029
6 bridges
What this shows Construction peaked in the 1950s, when 89 of the county's bridges still in the inventory were built, which is 18.1% of those with a recorded year. That cohort is now 65 to 74 years old in the 2024 inventory. Its average build year (1972) matches the Kansas average (1972).
How Lyon County compares with Kansas's closest counties by inventory size
The 5 Kansas counties nearest Lyon County in number of bridges, with their condition splits. Its 1% Poor share is the 3rd-lowest of these 6. Its average build year of 1972 against a peer-group mean of 1975 is in line with the group.
Showing the 5 closest of 103 Kansas counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| McPherson County | 586 | 66.6% | 32.8% | 0.7% | 1979 |
| Reno County | 573 | 51.8% | 42.1% | 6.1% | 1980 |
| Shawnee County | 563 | 62.9% | 34.1% | 3% | 1981 |
| Lyon County (this page) | 492 | 65.7% | 33.3% | 1% | 1972 |
| Barton County | 449 | 50.1% | 49.7% | 0.2% | 1959 |
| Marshall County | 402 | 49.8% | 39.6% | 10.7% | 1974 |
Each share is of that county's own total tracked bridges; peers are the counties with 5 or more bridges whose inventory size is closest to Lyon County's. Source: FHWA National Bridge Inventory, 2024 release.
Nationwide counties with similar inventory size or average build year
Two NBI-derived peer sets for Lyon County, both outside Kansas so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside KS (492 bridges here).
- Shasta County, CA · 492 bridges
- Greene County, MO · 493 bridges
- Canadian County, OK · 493 bridges
- Vermilion County, IL · 494 bridges
Similar average build year
Nearest mean year-built outside KS (1972 here).
- Santa Clara County, CA · avg 1972 · 964 bridges
- Madison County, AL · avg 1972 · 710 bridges
- Kern County, CA · avg 1972 · 668 bridges
- York County, PA · avg 1972 · 569 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Poor-condition bridges (5)
RD P (N.0-25.7)
PoorOver: COTTONWOOD RIVER
7.0W 0.5S NEOSHO RAPIDS, Lyon, KS
Built 1910 Load: 10.9 t ADT: 30
RD 70 931.7-540.7
PoorOver: STREAM
6.3W OF OLPE, Lyon, KS
Built 1939 Load: 13.6 t ADT: 10
RD H 939.0-544.1
PoorOver: MOON BRANCH CREEK
3.1W 2.1S OF OLPE, Lyon, KS
Built 1928 Load: 22.7 t ADT: 80
RD. T (T.0-281)
PoorOver: STREAM
5.5W 3.0N OF READING, Lyon, KS
Built 1971 Load: 22.7 t ADT: 30
RS 413 E.7-16.0
PoorOver: PESTER CREEK
IN AMERICUS, Lyon, KS
Built 1927 Load: 26.4 t ADT: 75
Read our methodology - how this data is sourced, computed, and verified.
Related
Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainBridges
Every figure on PlainBridges 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. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.