County profile · official public datasets

Allen County, KS

227 public highway bridges tracked in the FHWA National Bridge Inventory: 45.4% rated Good, 43.6% Fair, 11% Poor.

227
Public bridges: 45.4%
Good condition: 11%
Poor condition

The verdict

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

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

97th
of 104 on Poor share: 11%
Poor-condition share: 227
public highway bridges: 1959
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.

Allen County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Allen County ranks #97 of 104 Kansas counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 11%). Allen County, Kansas contains 227 public highway bridges. Roughly 45.4% are rated “Good,” 43.6% “Fair,” and 11% “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

227

Public highway bridges in Allen County

Good condition

45.4%

103 of 227 rated 7-9

Fair condition

43.6%

99 of 227 rated 5-6

Poor condition

11%

25 of 227 rated 4 or below

In-state Poor-share rank

#97 of 104

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

Condition distribution

Share of 227 NBI-tracked bridges by lowest applicable component rating.

Good

45.4% (103)

Fair

43.6% (99)

Poor

11% (25)

Allen County's Poor-condition bridges carry 1,925 vehicle crossings a day

That is 1.1% of the county's reported daily bridge traffic on 11% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 77 crossings a day against 1,320 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 227 of 227 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

66.1% of Allen County's bridges have passed the 50-year mark

150 of the 227 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 45.4% 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 15.6% of the county's Poor-condition bridge traffic

RS 4 over BRANCH OF DEER CREEK, built 1935, carries 300 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 25-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 1,925 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

3
1920s

3
1930s

75
1940s

23
1950s

17
1960s

22
1970s

13
1980s

34
1990s

15
2000s

12
2010s

6
2020s

4

What this shows Construction peaked in the 1930s, when 75 of the county's bridges still in the inventory were built, which is 33% of those with a recorded year. That cohort is now 85 to 94 years old in the 2024 inventory. Its average build year is 1959, 13 years older than the Kansas average of 1972.

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

The 5 Kansas counties nearest Allen County in number of bridges, with their condition splits. Its 11% Poor share is the 5th-lowest of these 6. Its average build year of 1959 against a peer-group mean of 1966 is 7 years older.

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

Bridge inventory size and condition shares for Allen County and the 5 Kansas counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Greenwood County	235	24.7%	54%	21.3%	1957
Clay County	231	51.9%	42.9%	5.2%	1970
Allen County (this page)	227	45.4%	43.6%	11%	1959
Lincoln County	225	33.3%	56.4%	10.2%	1957
Riley County	224	56.7%	37.9%	5.4%	1976
Ford County	223	50.2%	49.8%	0%	1972

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

Similar inventory size

Nearest county inventories outside KS (227 bridges here).

Yell County, AR · 227 bridges
McHenry County, IL · 227 bridges
LaPorte County, IN · 227 bridges
Rush County, IN · 227 bridges

Similar average build year

Nearest mean year-built outside KS (1959 here).

Tulare County, CA · avg 1959 · 589 bridges
Nassau County, NY · avg 1959 · 328 bridges
Hampshire County, MA · avg 1959 · 259 bridges
Noble County, OH · avg 1959 · 208 bridges

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

All 227 Good 103 Fair 99 Poor 25

All bridges (227)

Sort:

Allen County Bridge Snapshot

Condition distribution

Allen County's Poor-condition bridges carry 1,925 vehicle crossings a day

66.1% of Allen County's bridges have passed the 50-year mark

One structure carries 15.6% of the county's Poor-condition bridge traffic

How Allen 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

All bridges (227)

RS 1 600 St.

Rhode Island Rd

RS 2096 1100 Rd

RS 2 Delaware Rd

LOCAL RD 15.8-T.0

RS 1 800 St.

RS 4 TEXAS RD

RS 4

RS 5 2800 St.

RS 6 2600 St

RS 6 2600 St

RS 7 2200 St

RS 1151

RS 1153 Arizona Rd

RS 1153 Arizona Rd

RS 1154

RS 1154

RS 1492 3400 St.

RS 1492 3400 St.

RS 1492 3400 St.

RS 1492 3400 St

Hawaii Rd 19.7-P.0

800 St. 4.0-I.6

RS 4 UTAH RD

RS 1154

2800 St 14.0-K.5

N. WASHINGTON AVE.

CAMERON STREET

4600 St. 23.0-B.4

RS 1

RS 1726

US54 HWY

RS 1131 Hawaii Rd

OLD US169 K57 HWY

OLD US169 K57 HWY

Idaho Rd 13.7-O.0

Iowa Rd 14.5-N.0

LOCAL RD 14.5-T.0

Hawaii Rd 16.8-P.0

Iowa Rd 18.2-N.0

LOCAL RD 18.2-S.0

LOCAL RD 20.9-S.0

4400 St 22.0-S.9

LOCAL RD 23.0-V.0

200 St 1.0-S.9

200 St. 1.0-T.8

LOCAL RD 1.6-A.0

400 Rd 2.0-O.4

LOCAL RD 4.2-L.0

1000th Rd 5.0-D.8

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