County profile · official public datasets

Johnson County, KS

781 public highway bridges tracked in the FHWA National Bridge Inventory: 75% rated Good, 23.6% Fair, 1.4% Poor.

781
Public bridges: 75%
Good condition: 1.4%
Poor condition

The verdict

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

Johnson County pairs a top-quartile lowest Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

Top 21%
lowest Poor share in state: 1.4%
Poor-condition share: 781
public highway bridges: 1992
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.

Johnson County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Johnson County ranks #22 of 104 Kansas counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 1.4%). Johnson County, Kansas contains 781 public highway bridges. Roughly 75% are rated “Good,” 23.6% “Fair,” and 1.4% “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

781

Public highway bridges in Johnson County

Good condition

75%

586 of 781 rated 7-9

Fair condition

23.6%

184 of 781 rated 5-6

Poor condition

1.4%

11 of 781 rated 4 or below

In-state Poor-share rank

#22 of 104

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

Condition distribution

Share of 781 NBI-tracked bridges by lowest applicable component rating.

Good

75% (586)

Fair

23.6% (184)

Poor

1.4% (11)

Johnson County's Poor-condition bridges carry 61,312 vehicle crossings a day

That is 0.7% of the county's reported daily bridge traffic on 1.4% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 5,574 crossings a day against 11,009 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 781 of 781 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

18.4% of Johnson County's bridges have passed the 50-year mark

144 of the 781 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 75% 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 39.1% of the county's Poor-condition bridge traffic

COLLEGE BLVD over INDIAN CK, built 1976, carries 24,000 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 11-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 61,312 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

1
1920s

1
1930s

8
1940s

3
1950s

29
1960s

65
1970s

80
1980s

111
1990s

186
2000s

141
2010s

130
2020s

26

What this shows Construction peaked in the 1990s, when 186 of the county's bridges still in the inventory were built, which is 23.8% of those with a recorded year. That cohort is now 25 to 34 years old in the 2024 inventory. Its average build year is 1992, 20 years newer than the Kansas average of 1972.

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

The 5 Kansas counties nearest Johnson County in number of bridges, with their condition splits. Its 1.4% Poor share is the 2nd-lowest of these 6. Its average build year of 1992 against a peer-group mean of 1977 is 15 years newer.

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

Bridge inventory size and condition shares for Johnson County and the 5 Kansas counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Johnson County (this page)	781	75%	23.6%	1.4%	1992
Sumner County	659	50.2%	47.2%	2.6%	1978
Butler County	591	59.2%	34.7%	6.1%	1966
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

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

Similar inventory size

Nearest county inventories outside KS (781 bridges here).

Baltimore County, MD · 783 bridges
Hamilton County, OH · 783 bridges
El Paso County, TX · 783 bridges
Fulton County, GA · 775 bridges

Similar average build year

Nearest mean year-built outside KS (1992 here).

Wake County, NC · avg 1992 · 760 bridges
Benton County, AR · avg 1992 · 410 bridges
Nodaway County, MO · avg 1992 · 396 bridges
Cameron County, TX · avg 1992 · 355 bridges

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

All 781 Good 586 Fair 184 Poor 11

Good-condition bridges (586)

Sort:

Johnson County Bridge Snapshot

Condition distribution

Johnson County's Poor-condition bridges carry 61,312 vehicle crossings a day

18.4% of Johnson County's bridges have passed the 50-year mark

One structure carries 39.1% of the county's Poor-condition bridge traffic

How Johnson 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 (586)

WENONGA ROAD

215TH ST

HAROLD STREET #4

NB I-35 RAMP

SUNFLOWER RD

103RD ST

139TH. STREET #19

83RD. STREET

JOHNSON DRIVE

METCALF AVE.

MARTY ST.

183RD ST

191ST ST

NORESTON ST. #76

199TH ST

159TH ST

E SHERIDAN BR #28

NB I-35 RAMP

Antioch to SB I-35

167TH ST. #98

LAMAR AVE.

RAMP 69S-I435E

RENNER RD

NB Lone Elm Rd#93

MULBERRY STREET #9

SB Lone Elm Rd.#92

US 56 HWY

WB RAMP TO I35

RAMP I435S TO I35

207TH ST

163RD ST

RAMP K10EB-35N

RAMP 35SB-435N

ENSLEY LANE

RAMP NB35 TO EB435

W 159TH ST. #111

167TH ST

I435 HWY EB

K-7 HIGHWAY

87TH STREET

I-35

I435 HWY WB

119TH ST

162ND ST

119TH ST

163RD ST.

I-35 SB

167TH ST

TOMAHAWK CK PKWY

NALL AVE.

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