County profile · official public datasets

Lake County, IL

251 public highway bridges tracked in the FHWA National Bridge Inventory: 37.1% rated Good, 53% Fair, 10% Poor.

251
Public bridges
37.1%
Good condition
10%
Poor condition

The verdict

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

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

71st
of 102 on Poor share
10%
Poor-condition share
251
public highway bridges
1976
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.

Lake County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Lake County ranks #71 of 102 Illinois counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 10%). Lake County, Illinois contains 251 public highway bridges. Roughly 37.1% are rated “Good,” 53% “Fair,” and 10% “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

251

Public highway bridges in Lake County

Good condition

37.1%

93 of 251 rated 7-9

Fair condition

53%

133 of 251 rated 5-6

Poor condition

10%

25 of 251 rated 4 or below

In-state Poor-share rank

#71 of 102

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

Condition distribution

Share of 251 NBI-tracked bridges by lowest applicable component rating.

Good
37.1% (93)
Fair
53% (133)
Poor
10% (25)

Lake County's Poor-condition bridges carry 142,235 vehicle crossings a day

That is 4.1% of the county's reported daily bridge traffic on 10% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 5,689 crossings a day against 12,971 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 250 of 251 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

47% of Lake County's bridges have passed the 50-year mark

118 of the 251 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 37.1% 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 21.6% of the county's Poor-condition bridge traffic

IL 120 EB over DES PLAINES RIVER, built 1959, carries 30,700 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 142,235 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Lake County's bridges were built

251 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1950s, when 44 of the county's bridges still in the inventory were built, which is 17.5% of those with a recorded year. That cohort is now 65 to 74 years old in the 2024 inventory. Its average build year (1976) matches the Illinois average (1979).

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

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

The 5 Illinois counties nearest Lake County in number of bridges, with their condition splits. Its 10% Poor share is the 4th-lowest of these 6. Its average build year of 1976 against a peer-group mean of 1977 is in line with the group.

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

Bridge inventory size and condition shares for Lake County and the 5 Illinois counties closest to it in inventory size
County Bridges Poor
DeKalb County 261 13%
Jefferson County 260 6.2%
Effingham County 253 4.7%
Lake County (this page) 251 10%
Piatt County 246 6.1%
Macoupin County 242 17.8%

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

Similar inventory size

Nearest county inventories outside IL (251 bridges here).

Similar average build year

Nearest mean year-built outside IL (1976 here).

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

All 251 Good 93 Fair 133 Poor 25

Poor-condition bridges (25)

DILLEYS ROAD

Poor

Over: MILL CREEK

.13 E OF TOLL RD, Lake, IL

Built 2002 Load: 0.0 t ADT: 5,600

MS-4061 (BEECH ST)

Poor

Over: RAVINE

1.5 M N LAKE COOK RD, Lake, IL

Built 1957 Load: 0.0 t ADT: 300

GREENWOOD AVE

Poor

Over: UPRR

0.5 M E SHERIDAN RD, Lake, IL

Built 1972 Load: 0.0 t ADT: 250

RINGWOOD ROAD SOUT

Poor

Over: RAVINE

RINGWOOD AT SHERIDAN, Lake, IL

Built 1913 Load: 9.4 t ADT: 475

SAMPSON STREET

Poor

Over: PETTIBONE CREEK

0.5 KM S OF DECATUR AVE, Lake, IL

Built 1926 Load: 10.9 t ADT: 1,260

US 14

Poor

Over: FLINT CREEK TRIB

0.2 Mi E OF IL 59, Lake, IL

Built 1937 Load: 11.0 t ADT: 24,300

GENESEE ST

Poor

Over: WAUKEGAN RIVER

ON GEN ST S OF WATER, Lake, IL

Built 1913 Load: 11.3 t ADT: 1,700

MS-1144 (WADE ST)

Poor

Over: RAVINE

1.5 M N LAKE COOK RD, Lake, IL

Built 1963 Load: 12.0 t ADT: 75

LAKE ROAD

Poor

Over: RAVINE

LAKE RD AT WOODBINE, Lake, IL

Built 1912 Load: 12.6 t ADT: 525

PARK AVE (W)

Poor

Over: SKOKIE DITCH

.2 M E 41, Lake, IL

Built 1950 Load: 17.5 t ADT: 6,150

MS-1130 (JUDSON AV

Poor

Over: RAVINE

.1 E C&NW 1 M N CO L, Lake, IL

Built 1963 Load: 25.6 t ADT: 300

FAU-1234 (OAK SP R

Poor

Over: DES PLAINES RIVER

.75 M E OF ILL 21, Lake, IL

Built 1967 Load: 32.4 t ADT: 2,800

WALDEN LANE

Poor

Over: RAVINE

WALDEN AT WESTLEIH, Lake, IL

Built 1914 Load: 32.4 t ADT: 175

VANPATTEN WOODS RO

Poor

Over: DESPLAINES RIVER

0.19 MI N IL 173, Lake, IL

Built 1991 Load: 32.4 t ADT: 550

MARKET ST-IL 120RM

Poor

Over: UNUSED LAND

200 FT E SHERIDAN RD, Lake, IL

Built 1966 Load: 33.4 t ADT: 450

SHERIDAN RD

Poor

Over: IL 176 (SCRANTON RD)

GREAT LAKES NTC, Lake, IL

Built 1923 Load: 34.3 t ADT: 4,300

WASHINGTON ST

Poor

Over: RR - UP

0.1 M E OF US 41, Lake, IL

Built 1961 Load: 34.3 t ADT: 16,400

FAU-1239 Rockland

Poor

Over: DesPlaines River

1.5 MI W I-94, Lake, IL

Built 1990 Load: 34.3 t ADT: 3,450

IL 120 WB

Poor

Over: DES PLAINES RIVER

2.5 M W OF US 41, Lake, IL

Built 1959 Load: 34.7 t ADT: 30,700

GREEN BAY RD.

Poor

Over: U.P.R.R.

0.6M.S.OF IL-176, Lake, IL

Built 1988 Load: 35.3 t ADT: 8,500

IL 120 EB

Poor

Over: DES PLAINES RIVER

2.6 M W OF US 41, Lake, IL

Built 1959 Load: 36.0 t ADT: 30,700

BELVIDERE ST

Poor

Over: C&NW RR& L.F.F-WAY.

JUST E O SHERIDAN RD, Lake, IL

Built 1966 Load: 39.5 t ADT: 900

TR-2601 Main St

Poor

Over: Squaw Creek

2.5MI W US12 N.IL134, Lake, IL

Built 1900 Load: 47.0 t ADT: 1,600

RIVERSIDE ISLAND D

Poor

Over: NIPPERSINK LAKE

0.5 MI E US12, Lake, IL

Built 1998 Load: 49.9 t ADT: 125

THOMPSON AVENUE

Poor

Over: DEAD DOG CREEK

0.3 Mi S of 1st ST, Lake, IL

Built 1955 Load: 76.8 t ADT: 650

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.