County profile · official public datasets

Lee County, IL

371 public highway bridges tracked in the FHWA National Bridge Inventory: 39.9% rated Good, 48% Fair, 12.1% Poor.

371
Public bridges: 39.9%
Good condition: 12.1%
Poor condition

The verdict

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

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

83rd
of 102 on Poor share: 12.1%
Poor-condition share: 371
public highway bridges: 1980
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.

Lee County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Lee County ranks #83 of 102 Illinois counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 12.1%). Lee County, Illinois contains 371 public highway bridges. Roughly 39.9% are rated “Good,” 48% “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

371

Public highway bridges in Lee County

Good condition

39.9%

148 of 371 rated 7-9

Fair condition

48%

178 of 371 rated 5-6

Poor condition

12.1%

45 of 371 rated 4 or below

In-state Poor-share rank

#83 of 102

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

Condition distribution

Share of 371 NBI-tracked bridges by lowest applicable component rating.

Good

39.9% (148)

Fair

48% (178)

Poor

12.1% (45)

Lee County's Poor-condition bridges carry 9,240 vehicle crossings a day

That is 1.4% of the county's reported daily bridge traffic on 11.9% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 210 crossings a day against 1,179 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 370 of 371 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

39.9% of Lee County's bridges have passed the 50-year mark

148 of the 371 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 39.9% 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 20.6% of the county's Poor-condition bridge traffic

CH 1 LOST NATION R over FRANKLIN CREEK, built 1957, carries 1,900 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 45-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 9,240 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

4
1920s

1
1930s

8
1940s

2
1950s

30
1960s

49
1970s

65
1980s

97
1990s

54
2000s

35
2010s

23
2020s

3

What this shows Construction peaked in the 1980s, when 97 of the county's bridges still in the inventory were built, which is 26.1% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year (1980) matches the Illinois average (1979).

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

The 5 Illinois counties nearest Lee County in number of bridges, with their condition splits. Its 12.1% Poor share is the 3rd-lowest of these 6. Its average build year of 1980 against a peer-group mean of 1979 is in line with the group.

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

Bridge inventory size and condition shares for Lee County and the 5 Illinois counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Ogle County	377	46.2%	46.2%	7.7%	1981
Bureau County	375	41.3%	43.5%	15.2%	1978
Lee County (this page)	371	39.9%	48%	12.1%	1980
Tazewell County	358	25.4%	60.1%	14.5%	1976
Fayette County	357	56.6%	38.4%	5%	1976
Peoria County	352	24.1%	57.7%	18.2%	1983

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

Similar inventory size

Nearest county inventories outside IL (371 bridges here).

Genesee County, MI · 371 bridges
Carroll County, MO · 371 bridges
Fayette County, TX · 371 bridges
Clinton County, IA · 372 bridges

Similar average build year

Nearest mean year-built outside IL (1980 here).

Tulsa County, OK · avg 1980 · 1,135 bridges
Miami-Dade County, FL · avg 1980 · 1,057 bridges
Pulaski County, AR · avg 1980 · 721 bridges
McLennan County, TX · avg 1980 · 714 bridges

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

All 371 Good 148 Fair 178 Poor 45

All bridges (371)

Sort:

Lee County Bridge Snapshot

Condition distribution

Lee County's Poor-condition bridges carry 9,240 vehicle crossings a day

39.9% of Lee County's bridges have passed the 50-year mark

One structure carries 20.6% of the county's Poor-condition bridge traffic

How Lee 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 (371)

I 39 & US 51 SB

I-88 WB

IL 251

IL 2 WB

CH 35 NELSON RD

I 39 & US 51 NB

US 30

US 52 & IL 2 & IL

I 39&US 51

I-88 EB

I 39 & US 51 SB

I 39 & US 51 NB

ILL ROUTE 26

I-88 WB

I-88 WB

I-88 WB

ILL 38

ILL 251

US ROUTE 30

PAW PAW RD

US 30

I-88

US ROUTE 52

I-88

I 39&US 51

I 39&US 51

I-88

I-88 (E-W TOLLWAY)

PARIS RD

CARTER RD

GERMAN ROAD

CH 5 INLET RD

GITTLESON RD

HAYES RD

WOODLAWN ROAD

GRAND DETOUR RD

THORPE RD

COUNTY LINE RD

ROCK ISLAND ROAD

LEE ROAD

MC GIRR ROAD

LEE ROAD

SHAW ROAD

MERIDIAN ROAD

TR-268 (GERMAN RD)

FAS 182 ASHTON RD

CH 15 INDIAN HEAD

SHADY OAKS ROAD

IL 26

US ROUTE 52

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