County profile · official public datasets

Kendall County, IL

132 public highway bridges tracked in the FHWA National Bridge Inventory: 52.3% rated Good, 35.6% Fair, 12.1% Poor.

132
Public bridges: 52.3%
Good condition: 12.1%
Poor condition

The verdict

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

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

82nd
of 102 on Poor share: 12.1%
Poor-condition share: 132
public highway bridges: 1990
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.

Kendall County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Kendall County ranks #82 of 102 Illinois counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 12.1%). Kendall County, Illinois contains 132 public highway bridges. Roughly 52.3% are rated “Good,” 35.6% “Fair,” and 12.1% “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.

Total bridges

132

Public highway bridges in Kendall County

Good condition

52.3%

69 of 132 rated 7-9

Fair condition

35.6%

47 of 132 rated 5-6

Poor condition

12.1%

16 of 132 rated 4 or below

In-state Poor-share rank

#82 of 102

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

Condition distribution

Share of 132 NBI-tracked bridges by lowest applicable component rating.

Good

52.3% (69)

Fair

35.6% (47)

Poor

12.1% (16)

Kendall County's Poor-condition bridges carry 10,125 vehicle crossings a day

That is 2.1% of the county's reported daily bridge traffic on 12.1% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 633 crossings a day against 3,457 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 132 of 132 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

19.7% of Kendall County's bridges have passed the 50-year mark

26 of the 132 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 52.3% 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 15.3% of the county's Poor-condition bridge traffic

CREEK RD over LITTLE ROCK CK, built 1995, carries 1,550 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 16-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 10,125 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

2
1930s

3
1940s

1
1950s

5
1960s

8
1970s

17
1980s

19
1990s

33
2000s

24
2010s

12
2020s

8

What this shows Construction peaked in the 1990s, when 33 of the county's bridges still in the inventory were built, which is 25% of those with a recorded year. That cohort is now 25 to 34 years old in the 2024 inventory. Its average build year is 1990, 11 years newer than the Illinois average of 1979.

How Kendall County compares with Illinois's closest counties by inventory size

The 5 Illinois counties nearest Kendall County in number of bridges, with their condition splits. Its 12.1% Poor share is the 6th-lowest of these 6. Its average build year of 1990 against a peer-group mean of 1982 is 8 years newer.

Showing the 5 closest of 101 Illinois counties eligible for comparison.

Bridge inventory size and condition shares for Kendall County and the 5 Illinois counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Henderson County	142	33.1%	54.9%	12%	1985
Perry County	136	38.2%	54.4%	7.4%	1981
Massac County	132	43.9%	47.7%	8.3%	1980
Monroe County	132	59.1%	34.1%	6.8%	1986
Kendall County (this page)	132	52.3%	35.6%	12.1%	1990
Johnson County	118	58.5%	39%	2.5%	1979

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

Similar inventory size

Nearest county inventories outside IL (132 bridges here).

St. Joseph County, MI · 132 bridges
Otero County, NM · 132 bridges
Prince George County, VA · 132 bridges
Suffolk city County, VA · 132 bridges

Similar average build year

Nearest mean year-built outside IL (1990 here).

Maricopa County, AZ · avg 1990 · 2,847 bridges
Tarrant County, TX · avg 1990 · 2,617 bridges
Fairfax County, VA · avg 1990 · 751 bridges
Guilford County, NC · avg 1990 · 736 bridges

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

All 132 Good 69 Fair 47 Poor 16

All bridges (132)

Sort:

Kendall County Bridge Snapshot

Condition distribution

Kendall County's Poor-condition bridges carry 10,125 vehicle crossings a day

19.7% of Kendall County's bridges have passed the 50-year mark

One structure carries 15.3% of the county's Poor-condition bridge traffic

How Kendall County compares with Illinois'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 (132)

US 52 FAP 607

PVT FIELD ENTR

CRIMMINS ROAD

MILLHURST ROAD TR

CHERRY RD

MS 0055 MEADOW LN

TR 125 BELL RD

WILDY ROAD

PENMAN RD.

CHURCH RD/MS0015

WHEELER RD

BR E AUX SABLE CRE

WILLOW LANE

OBRIEN RD

TR 58 WALKERRD

OBRIEN RD

MILLER RD

GRISWOLD SPRINGS R

CHURCH RD/MS0015

TR 86 ASHLEY RD

ASHLEY RD

FAU1555/BRISTOL RI

FAS-276 Fox Rv. Dr

IMMANUEL RD TR 74

TR 93 HELMAR RD

Fern Dell Road

TR 111 CHICAGO ROA

ADAMS ST

OLD POST ROAD

BARNABY DRIVE

PEARCES FORD

DOUGLAS RD

KLATT ST./MS 7006

RIVER ROAD(FAU 379

CONCORD DRIVE

IL 47

ORCHARD ROAD

ILL 126

ILL 126

FAU 3799/ River Ro

FOX RIVER DRIVE

US RTE 52

ILL 71

LISBON CENTER RD

IL 47

JOLIET ROAD

US 52

ILL 71

GALENA RD/FAU 2502

IL 47

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