How many bridges are in Illinois?

Illinois has 26,928 public highway bridges tracked in the FHWA National Bridge Inventory. View detailed condition data for each bridge on PlainBridges.

What percentage of bridges in Illinois are in Poor condition?

9.3% of bridge records in Illinois are in Poor condition, meaning the lowest applicable major-component rating is 4 or below, compared with 7.5% across state inventories.

State profile · Near median Poor share

Illinois bridge safety

Name: Illinois public highway bridge inventory (FHWA NBI)
Creator: PlainBridges
License: https://creativecommons.org/publicdomain/zero/1.0/

According to the Federal Highway Administration's 2024 National Bridge Inventory, condition ratings, load ratings, and Poor-condition shares for every public highway bridge in Illinois.

Compiled by PlainBridges

26,928
Public bridges: 45.6%
Good condition: 9.3%
Poor condition

Illinois holds 26,928 public highway bridges (#2 of 52 by inventory) with a 9.35% Poor share (#12 of 52 by Poor share).

That is 9.3% of the state's inventory, against an average of 7.5% across the 54 states and territories with Poor-rated bridges on file, which places it 41 of 54 ordered from the lowest Poor share upward. A bridge is rated Poor when its weakest applicable component scores 4 or below on the inspecting agency's 0-9 scale, so the category is a maintenance and funding signal rather than a closure order or a live crossing-safety verdict.

Inventory: FHWA NBI 2024 · last ETL August 2026

Total Bridges

26,928

Public highway bridges in Illinois

Good Condition

45.6%

12,289 bridges rated 7-9

-4.4pp vs 50% benchmark

Poor Condition

9.3%

2,517 bridges whose lowest applicable component is rated 0-4

1.8pp vs national avg 7.5%

Illinois vs national bridge condition

Illinois - Good condition share 45.6%

National avg

Share of bridges rated 7-9 on the FHWA 0-9 scale (deck, superstructure, substructure all good).

Illinois - Poor-condition share 31.2%

National avg

Lower is better. Bar maxes at 30% (worst-state ceiling). National average sits at 7.5%.

Inventory size and Poor-condition share are different measures: Illinois has 26,928 bridges and a 9.3% Poor-condition share in the 2024 NBI, rank #41 of 54 jurisdictions ordered from the lowest share upward. The dashed comparisons mark the national average state rate and the midpoint of the plotted inventory range; neither is a live safety or closure threshold.

Illinois vs all states by public bridge inventory

Where this state's FHWA NBI public-highway bridge count sits among every state and territory on PlainBridges

26,928 2nd of 54 higher than 52 of 54 states

States and territories, banded by public bridge inventory size

Each bar is a band; taller bars hold more states. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.

Source FHWA National Bridge Inventory · 2024

Read the rank neighborhood for Illinois

The highlighted point is Illinois: 26,928 bridges and 9.35% in Poor condition, rank #41 of 54 jurisdictions ordered from the lowest share upward. The five jurisdictions immediately above and below Illinois on that same Poor-share ordering:

Massachusetts: 5,295 bridges · 8.88% Poor
Missouri: 24,618 bridges · 8.95% Poor
Illinois: 26,928 bridges · 9.35% Poor
New York: 17,642 bridges · 9.43% Poor
North Dakota: 4,255 bridges · 10.98% Poor

The full national sortable table lives on the rankings page.

Material families in Illinois

Exclusive FHWA material families across all 26,928 bridges in this state; continuous variants fold into the parent family. Orthogonal to the Poor-share scatter above.

Concrete 8,689 bridges (32%) Prestressed concrete 11,156 bridges (41%) Steel 6,939 bridges (26%) Wood or timber 71 bridges (0%) Other 73 bridges (0%)

Who maintains Illinois’s inventory

State agency holds 31.3% of the 26,928 public highway bridges filed under Illinois in the 2024 NBI, the agency-of-record split for this state, not a condition verdict.

State agency 8,429 bridges (31%) County agency 4,162 bridges (15%) Local agency 14,219 bridges (53%) Federal agency 36 bridges (0%) Other 82 bridges (0%)

When Illinois’s bridges were built

Pre-1950 construction accounts for 11.2% of the 26,928 bridges with a recorded original year in Illinois. Era bands are orthogonal to the Poor-share ranking above.

Pre-1950 3,007 bridges (11%) 1950–1979 8,649 bridges (32%) 1980–1999 9,203 bridges (34%) 2000+ 6,069 bridges (23%)

Condition Distribution

Bridge inventory deck-condition mix - Illinois (FHWA NBI)

Counties (102)

Adams 319 Alexander 93 Bond 162 Boone 109 Brown 71 Bureau 375 Calhoun 81 Carroll 179 Cass 77 Champaign 727 Christian 321 Clark 230 Clay 166 Clinton 190 Coles 304 Cook 1721 Crawford 197 Cumberland 169 De Witt 192 DeKalb 261 Douglas 232 DuPage 344 Edgar 278 Edwards 79 Effingham 253 Fayette 357 Ford 302 Franklin 310 Fulton 210 Gallatin 82 Greene 162 Grundy 269 Hamilton 165 Hancock 292 Hardin 61 Henderson 142 Henry 328 Iroquois 570 Jackson 228 Jasper 181 Jefferson 260 Jersey 113 Jo Daviess 193 Johnson 118 Kane 336 Kankakee 344 Kendall 132 Knox 304 LaSalle 528 Lake 251 Lawrence 185 Lee 371 Livingston 579 Logan 292 Macon 346 Macoupin 242 Madison 523 Marion 296 Marshall 155 Mason 86 Massac 132 McDonough 209 McHenry 227 McLean 624 Menard 89 Mercer 163 Monroe 132 Montgomery 261 Morgan 234 Moultrie 172 Ogle 377 Peoria 352 Perry 136 Piatt 246 Pike 330 Pope 88 Pulaski 108 Putnam 50 Randolph 149 Richland 151 Rock Island 272 Saline 185 Sangamon 466 Schuyler 114 Scott 99 Shelby 335 St. Clair 486 Stark 93 Stephenson 342 Tazewell 358 Union 192 Vermilion 494 Wabash 89 Warren 199 Washington 233 Wayne 266 White 214 Whiteside 278 Will 649 Williamson 201 Winnebago 467 Woodford 223

Illinois vs nearby ranks

Adjacent states by Poor-condition share (lower share = better)

States are ranked by the share of bridges whose lowest applicable component rating is 4 or below. This describes recorded condition; it does not measure funding effectiveness or live crossing safety. States here sit immediately above and below Illinois on the same metric.

Massachusetts

8.88% top marginal rate

Structure: Progressive
Burden @ $100K: $5,295

Missouri

8.95% top marginal rate

Structure: Progressive
Burden @ $100K: $24,618

Selected

Illinois

9.35% top marginal rate

Structure: Progressive
Burden @ $100K: $26,928

New York

9.43% top marginal rate

Structure: Progressive
Burden @ $100K: $17,642

North Dakota

10.98% top marginal rate

Structure: Progressive
Burden @ $100K: $4,255

Bridges Needing Most Attention in Illinois

Six lowest-condition bridges in Illinois, ranked by the portal's composite display score. Inspection intervals are risk-based under current NBIS rules.

TR 416

Poor

Over: MCKEE CRK

4.7 MI W KELLERVILLE, Adams, IL

Built 1905 Load: 0.0 t ADT: 10

CH 11

Poor

Over: SOUTH FORKBEAR CREEK

3.96 MI N CAMP POINT, Adams, IL

Built 1975 Load: 0.0 t ADT: 725

FAS 945

Poor

Over: CLEAR CREEK DITCH

2.5 MI E OF MCCLURE, Alexander, IL

Built 1959 Load: 0.0 t ADT: 1,100

CH 4

Poor

Over: SPRING BRANCH

4.5M N KEYSPORT, Bond, IL

Built 1973 Load: 0.0 t ADT: 50

TR-164

Poor

Over: Little Beaver Creek

2 MI S DUDLEYVILLE, Bond, IL

Built 1965 Load: 0.0 t ADT: 50

TR 85

Poor

Over: MASTERS CREEK

3 MI SE OF OHIO, Bureau, IL

Built 1965 Load: 0.0 t ADT: 25

All Bridges in Illinois

Sort by:

Illinois vs national bridge condition

Material families in Illinois

Who maintains Illinois’s inventory

When Illinois’s bridges were built

Condition Distribution

Counties (102)

Bridges Needing Most Attention in Illinois

TR 416

CH 11

FAS 945

CH 4

TR-164

TR 85

All Bridges in Illinois

TR 96

TR 341

TR 455

TR 85

FAS 496(CH 14)

TR 205

TR 385

TR 65

TR 65

TR 428

TR 169

TR 131

TR 89

TR 69 B

TR 69 A

TR 231

TR 492 A

TR 47

TR 436

TR 54 A

TR 90 A

CH 11

FAS 1507(TR 249)

TR 216

TR 44

TR 275

TR 27

TR 315

TR 217

TR 443

TR 12

TR 365

TR 6 A

TR 383

TR 35

TR 41

TR 421

TR 445

TR 13

TR 344

TR 13

TR 443

TR 28

TR 147

TR 145

TR 6

TR 397

FAS 511(CH 16)

TR 41

TR 261

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