County profile · official public datasets

Logan County, IL

292 public highway bridges tracked in the FHWA National Bridge Inventory: 29.8% rated Good, 62% Fair, 8.2% Poor.

292
Public bridges
29.8%
Good condition
8.2%
Poor condition

The verdict

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

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

56th
of 102 on Poor share
8.2%
Poor-condition share
292
public highway bridges
1975
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.

Logan County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Logan County ranks #56 of 102 Illinois counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 8.2%). Logan County, Illinois contains 292 public highway bridges. Roughly 29.8% are rated “Good,” 62% “Fair,” and 8.2% “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

292

Public highway bridges in Logan County

Good condition

29.8%

87 of 292 rated 7-9

Fair condition

62%

181 of 292 rated 5-6

Poor condition

8.2%

24 of 292 rated 4 or below

In-state Poor-share rank

#56 of 102

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

Condition distribution

Share of 292 NBI-tracked bridges by lowest applicable component rating.

Good
29.8% (87)
Fair
62% (181)
Poor
8.2% (24)

Logan County's Poor-condition bridges carry 9,370 vehicle crossings a day

That is 1.5% of the county's reported daily bridge traffic on 8.2% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 390 crossings a day against 1,239 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 291 of 292 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

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

146 of the 292 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 29.8% 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 62.2% of the county's Poor-condition bridge traffic

I-155 & RAMPS A & over S FK PRAIRIE CREEK, built 1990, carries 5,825 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 24-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 9,370 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Logan County's bridges were built

292 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1970s, when 72 of the county's bridges still in the inventory were built, which is 24.7% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year (1975) matches the Illinois average (1979).

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

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

The 5 Illinois counties nearest Logan County in number of bridges, with their condition splits. Its 8.2% Poor share is the 3rd-lowest of these 6. Its average build year of 1975 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 Logan County and the 5 Illinois counties closest to it in inventory size
County Bridges Poor
Coles County 304 8.9%
Knox County 304 11.2%
Ford County 302 6.3%
Marion County 296 6.4%
Hancock County 292 20.2%
Logan County (this page) 292 8.2%

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

Similar inventory size

Nearest county inventories outside IL (292 bridges here).

Similar average build year

Nearest mean year-built outside IL (1975 here).

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

All bridges (292)

CH 63E

Fair

Over: SALT CK TRIB

3.5 MI W BROADWELL, Logan, IL

Built 1938 Load: 12.6 t ADT: 50

BURTONVIEW RD

Fair

Over: LOCAL DRAINAGE

2.5 W .5 N HARTSBURG, Logan, IL

Built 1940 Load: 13.0 t ADT: 450

TR 207

Fair

Over: LAKE FORK CK TRIB.

2 MI NW LAKE FORK, Logan, IL

Built 1900 Load: 13.6 t ADT: 20

TR 19

Fair

Over: KICKAPOO CK OVERFLOW

2.5 E 1 MI N ATLANTA, Logan, IL

Built 1900 Load: 14.3 t ADT: 50

ROCKY FORD RD

Fair

Over: LOCAL DRAINAGE

3.5 MI N BROADWELL, Logan, IL

Built 1947 Load: 14.6 t ADT: 150

TR 298

Fair

Over: S FORK LAKE FORK CK

3.5 S 1 MI E NARITA, Logan, IL

Built 1955 Load: 17.2 t ADT: 20

TR 3

Fair

Over: LOCAL DRAINAGE

1 MI N 3 MI E EMDEN, Logan, IL

Built 1962 Load: 17.2 t ADT: 25

TR 59

Fair

Over: PRAIRIE CK TRIB

2.5 N 1.5 E NEW HLND, Logan, IL

Built 1941 Load: 17.5 t ADT: 50

TR 81A

Fair

Over: LOCAL DRAINAGE

1 MI S LAWNDALE, Logan, IL

Built 1955 Load: 17.8 t ADT: 20

TR 92

Fair

Over: LOCAL DRAINAGE

2 MI S BROADWELL, Logan, IL

Built 1957 Load: 17.8 t ADT: 100

TR 45

Fair

Over: Prairie Creek Tributary

3.0 mi W of I-155, Logan, IL

Built 1957 Load: 18.5 t ADT: 100

TR 233

Fair

Over: LAKE FK CK TRIB

1.5 N 1 MI W CORNLND, Logan, IL

Built 1961 Load: 19.1 t ADT: 50

IL 121

Fair

Over: FORK DEER CREEK

1M S IL 10 - LINCOLN, Logan, IL

Built 1964 Load: 19.4 t ADT: 3,650

TR 218

Fair

Over: LAKE FORK CK

2 E 2.5 MI S LAKE FK, Logan, IL

Built 1968 Load: 19.8 t ADT: 25

TR 176

Fair

Over: LAKE FORK CK TRIB

1 W 1MI S LAKE FORK, Logan, IL

Built 1959 Load: 20.4 t ADT: 100

TR 176

Fair

Over: LOCAL DRAINAGE

2 E 1 MI S CORNLAND, Logan, IL

Built 1954 Load: 20.4 t ADT: 50

FAS 566

Fair

Over: LOCAL DRAINAGE

CENTER OF ELKHART, Logan, IL

Built 1900 Load: 20.7 t ADT: 1,200

0083

Fair

Over: LOCAL DRAINAGE

4 MI N BEASON, Logan, IL

Built 1900 Load: 20.7 t ADT: 20

TR 9

Fair

Over: PRAIRIE CK

1 MI W EMDEN, Logan, IL

Built 1964 Load: 20.9 t ADT: 75

ATANTA-BEASON RD

Fair

Over: KICKAPOO CK

4 MI S ATLANTA, Logan, IL

Built 1948 Load: 21.1 t ADT: 400

TR 176

Fair

Over: HUNTER SLOUGH

2 E .5 MI S CORNLAND, Logan, IL

Built 1955 Load: 21.1 t ADT: 100

TR 187

Fair

Over: SALT CK TRIB

3 W 2.5 MI N MT PLSK, Logan, IL

Built 1958 Load: 21.1 t ADT: 50

TR 60

Fair

Over: SUGAR CR FLOOD PLAIN

4 MI E NEW HOLLAND, Logan, IL

Built 1989 Load: 21.1 t ADT: 20

TR 218

Fair

Over: LOCAL DRAINAGE

3 MI E LAKE FORK, Logan, IL

Built 1962 Load: 22.4 t ADT: 100

TR 212

Fair

Over: LAKE FORK CK TRIB

1 MI E LAKE FORK, Logan, IL

Built 1958 Load: 22.7 t ADT: 20

TR 198

Fair

Over: N FK LAKE FORK DITCH

1.5 S 1.5 E CHESTNUT, Logan, IL

Built 1967 Load: 23.0 t ADT: 25

TR 235

Fair

Over: LAKE FORK CK TRIB

1 MI S LAKE FORK, Logan, IL

Built 1956 Load: 23.0 t ADT: 50

SKELTON RD

Fair

Over: DEER CK BRANCH

5 SE OF LINCOLN, Logan, IL

Built 1963 Load: 23.5 t ADT: 75

TR 23

Fair

Over: LOCAL DRAINAGE

1 MI N 4.5MI W HARTS, Logan, IL

Built 1975 Load: 24.0 t ADT: 50

BEASON-CHESTNUT RD

Fair

Over: SALT CK TRIB

1.5 MI N CHESTNUT, Logan, IL

Built 1945 Load: 24.3 t ADT: 350

NEW HOLLAND-SAN JO

Fair

Over: LOCAL DRAINAGE

4 N OF NEW HOLLAND, Logan, IL

Built 1960 Load: 24.3 t ADT: 150

TR 121

Fair

Over: LOCAL DRAINAGE

2 MI NE MIDDLETOWN, Logan, IL

Built 1955 Load: 24.3 t ADT: 50

TR 253

Fair

Over: N FORK LAKE FORK CR

3 S 1 MI W NARITA, Logan, IL

Built 1963 Load: 24.3 t ADT: 50

TR 286

Fair

Over: S FORK LAKE FORK CK

3.5 MI S NARITA, Logan, IL

Built 1965 Load: 24.3 t ADT: 50

TR 3

Fair

Over: LOCAL DRAINAGE

1.5 MI N EMDEN, Logan, IL

Built 1900 Load: 24.3 t ADT: 50

TR 185

Fair

Over: PIKE CR DR DITCH

4 NW OF ELKHART, Logan, IL

Built 1965 Load: 24.6 t ADT: 50

CENTRAL POINT RD

Fair

Over: DEER CK

1.5 E 2.5 N BEASON, Logan, IL

Built 1967 Load: 24.9 t ADT: 150

NIANTIC RD

Fair

Over: S FORK LAKE FORK CK

1.5 MI S LATHAM, Logan, IL

Built 1969 Load: 25.3 t ADT: 225

TR 199

Fair

Over: LAKE FORK CK. TRIB.

2 MI SE ELKHART, Logan, IL

Built 1974 Load: 25.3 t ADT: 75

BURTON VIEW RD

Fair

Over: SUGAR CK

2.3 MI N BURTONVIEW, Logan, IL

Built 1964 Load: 25.6 t ADT: 300

TR 188

Fair

Over: LAKE FORK CK

2 MI S LAKE FORK, Logan, IL

Built 1969 Load: 25.6 t ADT: 50

TR 41

Fair

Over: CLEAR CK

3.5 MI E ATLANTA, Logan, IL

Built 1970 Load: 25.8 t ADT: 75

CH 63E

Fair

Over: SALT CK TRIB

6 MI W BROADWELL, Logan, IL

Built 1938 Load: 25.9 t ADT: 50

CH 63E

Fair

Over: SALT CK TRIB

4 MI W BROADWELL, Logan, IL

Built 1938 Load: 25.9 t ADT: 50

JOHNSON SIPING RD

Fair

Over: DEER CK

3 E .5 MI S LINCOLN, Logan, IL

Built 1970 Load: 26.2 t ADT: 75

TR 253

Fair

Over: N FK LAKE FK OVERFL

3 S 1 MI W NARITA, Logan, IL

Built 1961 Load: 26.2 t ADT: 50

TR 194

Fair

Over: SALT CK TRIB

1.5 W 3 MI N MT PLSK, Logan, IL

Built 1970 Load: 26.2 t ADT: 20

TR 221

Fair

Over: LAKE FORK CK TR 1B

.5 N 1.5 MI E LK FK, Logan, IL

Built 1974 Load: 26.2 t ADT: 50

CH 15

Fair

Over: PIKE CK

2.5 MI S MIDDLETOWN, Logan, IL

Built 1963 Load: 26.9 t ADT: 450

US 136

Fair

Over: I-155

I-155/US 136 INTCHG, Logan, IL

Built 1991 Load: 27.5 t ADT: 2,350
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.