County profile · official public datasets

Logan County, KS

55 public highway bridges tracked in the FHWA National Bridge Inventory: 60% rated Good, 36.4% Fair, 3.6% Poor.

55
Public bridges: 60%
Good condition: 3.6%
Poor condition

The verdict

According to the Federal Highway Administration's 2024 National Bridge Inventory.

Logan County pairs a better-than-median Poor-condition share among rated counties in the state with an older average build year than the state inventory.

Top 43%
lowest Poor share in state: 3.6%
Poor-condition share: 55
public highway bridges: 1967
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.

Logan County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Logan County ranks #45 of 104 Kansas counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 3.6%). Logan County, Kansas contains 55 public highway bridges. Roughly 60% are rated “Good,” 36.4% “Fair,” and 3.6% “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.

Total bridges

Public highway bridges in Logan County

Good condition

60%

33 of 55 rated 7-9

Fair condition

36.4%

20 of 55 rated 5-6

Poor condition

3.6%

2 of 55 rated 4 or below

In-state Poor-share rank

#45 of 104

Among Kansas counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 55 NBI-tracked bridges by lowest applicable component rating.

Good

60% (33)

Fair

36.4% (20)

Poor

3.6% (2)

Logan County's Poor-condition bridges carry 1,070 vehicle crossings a day

That is 2.7% of the county's reported daily bridge traffic on 3.6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 535 crossings a day against 979 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 55 of 55 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

72.7% of Logan County's bridges have passed the 50-year mark

40 of the 55 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 60% 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 86.9% of the county's Poor-condition bridge traffic

US40 HWY over N FK SMOKY HILL RIVER, built 1957, carries 930 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 2-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 1,070 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1920s

2
1930s

3
1950s

19
1960s

12
1970s

5
1980s

7
1990s

4
2010s

1
2020s

2

What this shows Construction peaked in the 1950s, when 19 of the county's bridges still in the inventory were built, which is 34.5% of those with a recorded year. That cohort is now 65 to 74 years old in the 2024 inventory. Its average build year is 1967, 5 years older than the Kansas average of 1972.

How Logan County compares with Kansas's closest counties by inventory size

The 5 Kansas counties nearest Logan County in number of bridges, with their condition splits. Its 3.6% Poor share is the 4th-lowest of these 6. Its average build year of 1967 against a peer-group mean of 1964 is in line with the group.

Showing the 5 closest of 103 Kansas counties eligible for comparison.

Bridge inventory size and condition shares for Logan County and the 5 Kansas counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Kearny County	72	41.7%	58.3%	0%	1968
Edwards County	69	26.1%	69.6%	4.3%	1970
Hamilton County	68	88.2%	11.8%	0%	1955
Gray County	66	66.7%	33.3%	0%	1961
Logan County (this page)	55	60%	36.4%	3.6%	1967
Wallace County	44	54.5%	40.9%	4.5%	1966

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 Logan 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 Logan County, both outside Kansas so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside KS (55 bridges here).

Park County, CO · 55 bridges
Dixie County, FL · 55 bridges
Winnebago County, IA · 55 bridges
Gallatin County, KY · 55 bridges

Similar average build year

Nearest mean year-built outside KS (1967 here).

Los Angeles County, CA · avg 1967 · 3,547 bridges
Allegheny County, PA · avg 1967 · 1,294 bridges
Sonoma County, CA · avg 1967 · 609 bridges
Merced County, CA · avg 1967 · 528 bridges

Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.

All 55 Good 33 Fair 20 Poor 2

Good-condition bridges (33)

Sort:

Logan County Bridge Snapshot

Condition distribution

Logan County's Poor-condition bridges carry 1,070 vehicle crossings a day

72.7% of Logan County's bridges have passed the 50-year mark

One structure carries 86.9% of the county's Poor-condition bridge traffic

How Logan County compares with Kansas's closest counties by inventory size

Nationwide counties with similar inventory size or average build year

Similar inventory size

Similar average build year

Good-condition bridges (33)

US-83 HIWAY

K25 HWY

400 ROAD (RS 1594)

400 ROAD (RS 1594)

350 ROAD (RS 1512)

PLAINS RD (RS 272)

PLAINS RD (RS 272)

PLAINS RD (RS 272)

K25 HWY

PLAINS RD (RS 272)

GOLD RD (RS 1067)

ELK ROAD (RS 1067)

PLAINS RD (RS 272)

K25 HWY

K25 HWY

US-83 HWY

K25 HWY

390 ROAD (RS 1067)

I70 HWY WB

I70 HWY EB

ZEST RD (RS 1672)

LOCAL ROAD

230 ROAD (RS 1510)

BROADWAY ST

US83 HWY

US-40 HWY

US83 HWY

K25 HWY

US-83 HWY

BISON ROAD

QUAIL RD (RS 127)

220 ROAD (RS 1417)

US-83 HIWAY

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