County profile · official public datasets

McHenry County, IL

227 public highway bridges tracked in the FHWA National Bridge Inventory: 41.4% rated Good, 38.3% Fair, 20.3% Poor.

227
Public bridges
41.4%
Good condition
20.3%
Poor condition

The verdict

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

McHenry County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.

99th
of 102 on Poor share
20.3%
Poor-condition share
227
public highway bridges
1983
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.

McHenry County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, McHenry County ranks #99 of 102 Illinois counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 20.3%). McHenry County, Illinois contains 227 public highway bridges. Roughly 41.4% are rated “Good,” 38.3% “Fair,” and 20.3% “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 McHenry County

Good condition

41.4%

94 of 227 rated 7-9

Fair condition

38.3%

87 of 227 rated 5-6

Poor condition

20.3%

46 of 227 rated 4 or below

In-state Poor-share rank

#99 of 102

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

Condition distribution

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

Good
41.4% (94)
Fair
38.3% (87)
Poor
20.3% (46)

McHenry County's Poor-condition bridges carry 69,075 vehicle crossings a day

That is 5.9% of the county's reported daily bridge traffic on 20.3% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 1,502 crossings a day against 7,359 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.

34.4% of McHenry County's bridges have passed the 50-year mark

78 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 41.4% 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 16.6% of the county's Poor-condition bridge traffic

US 12 over NIPPERSINK CR OVERFL, built 1939, carries 11,500 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 46-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 69,075 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When McHenry County's bridges were built

227 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 2010s, when 44 of the county's bridges still in the inventory were built, which is 19.4% of those with a recorded year. That cohort is now 5 to 14 years old in the 2024 inventory. Its average build year (1983) matches the Illinois average (1979).

Source FHWA National Bridge Inventory (year built) As of 2024 NBI release

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

The 5 Illinois counties nearest McHenry County in number of bridges, with their condition splits. Its 20.3% Poor share is the 6th-lowest of these 6. Its average build year of 1983 against a peer-group mean of 1981 is in line with the group.

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

Bridge inventory size and condition shares for McHenry County and the 5 Illinois counties closest to it in inventory size
County Bridges Poor
Washington County 233 6%
Douglas County 232 1.3%
Clark County 230 4.8%
Jackson County 228 6.6%
McHenry County (this page) 227 20.3%
Woodford County 223 10.3%

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

Similar inventory size

Nearest county inventories outside IL (227 bridges here).

Similar average build year

Nearest mean year-built outside IL (1983 here).

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

All 227 Good 94 Fair 87 Poor 46

Good-condition bridges (94)

COUNTY LINE RD

Good

Over: GERYUNE CREEK

0.8 N OF DUNHAM ROAD, McHenry, IL

Built 1959 Load: 15.9 t ADT: 1,000

ALDEN ROAD

Good

Over: STREAM

0.6 S ALTENBERG RD, McHenry, IL

Built 1961 Load: 19.8 t ADT: 3,050

SO UNION RD

Good

Over: STREAM

0.3 N ADAMSON RD, McHenry, IL

Built 1964 Load: 24.3 t ADT: 200

ALGONQUIN ROAD

Good

Over: WOODS CRK W RANDALL

0.7 MI W RANDALL RD, McHenry, IL

Built 2007 Load: 25.9 t ADT: 22,300

Olcott Road

Good

Over: Unnamed Ditch

Olcott at Carmack, McHenry, IL

Built 2016 Load: 29.2 t ADT: 125

KEYSTONE ROAD

Good

Over: NIPPERSINK CR TRIB

0.9 MI S TRYON GROVE, McHenry, IL

Built 1990 Load: 29.8 t ADT: 1,300

RAWSON BRIDGE ROAD

Good

Over: FOX RIVER

.8 MI W LAKE CO LINE, McHenry, IL

Built 1982 Load: 30.5 t ADT: 6,050

OBRIEN ROAD

Good

Over: NIPPERSINK CREEK

1.5 MI W OF IL 47, McHenry, IL

Built 1976 Load: 32.1 t ADT: 850

RAKOW RD (CH V-29)

Good

Over: CRYSTAL CREEK

0.24 MI. N OF ACKMAN, McHenry, IL

Built 1994 Load: 32.4 t ADT: 30,600

GRAF ROAD

Good

Over: LITTLE BEAVER CREEK

.1M E OF COUNTY LINE, McHenry, IL

Built 2005 Load: 32.4 t ADT: 250

MARENGO ROAD

Good

Over: MOKELER CREEK

0.1 S. OF ILL 173, McHenry, IL

Built 2014 Load: 32.4 t ADT: 2,350

CRYSTAL LAKE RD

Good

Over: WOODS CREEK

0.75 MI N ALGONQUIN, McHenry, IL

Built 2006 Load: 32.4 t ADT: 3,200

ACKMAN RD

Good

Over: TRIB KISHWAUKEE RVR

0.3 MI W IL 47, McHenry, IL

Built 2006 Load: 32.4 t ADT: 2,400

KREUTZER ROAD

Good

Over: S BRNCH KISHWKEE RVR

.5MI W OF IL 47, McHenry, IL

Built 2014 Load: 32.4 t ADT: 2,650

BULLVALLEY RD.

Good

Over: BOONE CREEK

.4M.W.VALLEY HILL RD, McHenry, IL

Built 1991 Load: 32.4 t ADT: 2,350

OAK STREET

Good

Over: CRYSTAL CR

.24M W OF PYOTT, McHenry, IL

Built 1993 Load: 32.4 t ADT: 1,950

Jessie Road

Good

Over: Crystal Creek

0.3 M W of Pyott Rd, McHenry, IL

Built 2014 Load: 32.4 t ADT: 450

Woods Creek Lane

Good

Over: Woods Creek

0.3 mi S of Bunker H, McHenry, IL

Built 2021 Load: 32.4 t ADT: 800

Bunker Hill Drive

Good

Over: Woods Creek

0.67 mi W Randall Road, McHenry, IL

Built 1999 Load: 32.4 t ADT: 6,500

CHARLES MILLER Rd

Good

Over: FOX RIVER

0.1 MI W RIVER RD, McHenry, IL

Built 2013 Load: 33.0 t ADT: 8,150

IL 173

Good

Over: MOKELLER CREEK

0.08 M W OF US 14, McHenry, IL

Built 1993 Load: 33.4 t ADT: 5,500

HARMONY ROAD

Good

Over: UNNAMED CREEK

.6M NW OF HARMDY HIL, McHenry, IL

Built 2004 Load: 34.3 t ADT: 2,350

IL 31 & 120

Good

Over: BOONE CREEK

1.6M W OF CHAPEL HIL, McHenry, IL

Built 1990 Load: 34.7 t ADT: 30,300

Jankowski Rd/ TR85

Good

Over: Slough Creek

0.7M W IL47, McHenry, IL

Built 1975 Load: 35.0 t ADT: 175

US 14

Good

Over: RUSH CREEK

1.2 S HARVARD, McHenry, IL

Built 1984 Load: 35.3 t ADT: 15,200

IL 31

Good

Over: DUTCH CREEK

6.2 M S OF US 12, McHenry, IL

Built 1978 Load: 35.3 t ADT: 23,400

ALLENDALE ROAD

Good

Over: BR NIPPERSINK CR

1.5 E IL 47, McHenry, IL

Built 2009 Load: 35.3 t ADT: 750

IL 23

Good

Over: KISHWAUKEE R OVERFLO

1.3 MI. N. US 20, McHenry, IL

Built 2009 Load: 36.0 t ADT: 6,450

ALGONQUIN ROAD

Good

Over: CRYSTAL CREEK

02M W OF PYOTT, McHenry, IL

Built 2004 Load: 36.3 t ADT: 31,600

FRANKLINVILLE RD

Good

Over: TRIB KISH RIVER

0.1 MI S PERKINS RD, McHenry, IL

Built 2016 Load: 36.3 t ADT: 1,500

ANTHONY RD

Good

Over: I 90

I 90 2.8 MI W ILL 23, McHenry, IL

Built 2015 Load: 36.3 t ADT: 50

Harmony Riley Road

Good

Over: Interstate 90

I-90 1M W of ILL 23, McHenry, IL

Built 2014 Load: 36.3 t ADT: 1,450

CARMACK ROAD

Good

Over: RUSH CREEK

0.5 W COX ROAD, McHenry, IL

Built 1993 Load: 36.9 t ADT: 250

DEERPASS ROAD

Good

Over: KISH RIVER N CHANNEL

0.7 MI N IL RTE 176, McHenry, IL

Built 2019 Load: 36.9 t ADT: 1,650

Getty Road

Good

Over: Interstate 90

0.5 M N of Dekalb CO, McHenry, IL

Built 2013 Load: 36.9 t ADT: 275

MUSGRAVE PARKWAY

Good

Over: UNAMED TRIB COON CRK

0.4 MI W SEEMAN RD, McHenry, IL

Built 2005 Load: 37.3 t ADT: 100

ALGONQUIN ROAD

Good

Over: WOODS CREEK

.4M W OF PYOTT RD, McHenry, IL

Built 2004 Load: 37.9 t ADT: 31,600

UNION ROAD / CHT-6

Good

Over: S BR KISHWAUKEE RIV

0.5 MI S IL RTE 176, McHenry, IL

Built 2011 Load: 37.9 t ADT: 1,800

LAWRENCE RD

Good

Over: TRIB LAWRENCE CREEK

1 MI N OF RAMER RD, McHenry, IL

Built 2016 Load: 37.9 t ADT: 850

US 14

Good

Over: IL 31

US 14 & ILL 31 INCHG, McHenry, IL

Built 1999 Load: 38.2 t ADT: 24,700

IL 173

Good

Over: MOKELLER CREEK

0.39 M W OF US 14, McHenry, IL

Built 1999 Load: 38.2 t ADT: 5,500

IL 173

Good

Over: MOKELLER CREEK

0.26 M W OF US 14, McHenry, IL

Built 1999 Load: 38.2 t ADT: 5,500

BOTTERMAN ROAD

Good

Over: UNAMED TRIB COON CRK

0.4 MI W SEEMAN RD, McHenry, IL

Built 2004 Load: 38.9 t ADT: 350

IL 176

Good

Over: KISHWAUKEE RIVER

2 M E OF IL 47, McHenry, IL

Built 2000 Load: 39.2 t ADT: 10,200

ALDEN ROAD

Good

Over: BR NIPPERSINK CREEK

0.2MI.N OF IL 173, McHenry, IL

Built 2010 Load: 39.2 t ADT: 2,300

GRAF ROAD/TR-37

Good

Over: LAWRENCE CREEK

.3MNW OAK GR/HARVARD, McHenry, IL

Built 2011 Load: 39.5 t ADT: 375

Kishwaukee Valley

Good

Over: Rush Creek Tributary

0.20 Mi E of Root Rd, McHenry, IL

Built 2021 Load: 39.9 t ADT: 3,600

IL 173

Good

Over: N BR NIPPERSINK CR

0.5 M W OF US 12, McHenry, IL

Built 1932 Load: 40.8 t ADT: 5,100

IL 176

Good

Over: S BR KISHWAUKEE RIV

1.1 M E IL 23, McHenry, IL

Built 2008 Load: 40.8 t ADT: 5,700

S. Harrison Street

Good

Over: Crystal Lake Overflo

0.1 MI S IL 62, McHenry, IL

Built 2023 Load: 40.8 t ADT: 1,400

Read our methodology - how this data is sourced, computed, and verified.

Related

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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.