State profile · Above median Poor share

Iowa bridge safety

Condition ratings, load ratings, and Poor-condition data for every public highway bridge in Iowa, based on the FHWA National Bridge Inventory.

20,753
Public bridges
36.5%
Good condition
20.0%
Poor condition

Data updated May 2026

Total Bridges

20,753

Public highway bridges in Iowa

Good Condition

36.5%

7,582 bridges rated 7-9

-13.5pp vs 50% benchmark

Poor Condition

20.0%

4,153 bridges whose lowest applicable component is rated 0-4

13.0pp vs national avg 7.0%

Iowa vs national bridge condition

Iowa - Good condition share 36.5%
National avg

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

Iowa - Poor-condition share 66.7%
National avg

Lower is better. Bar maxes at 30% (worst-state ceiling). National average sits at 7.0%.

Condition Distribution

Iowa38.5%40.4%21.1%GoodFairPoor
Bridge inventory deck-condition mix - Iowa (FHWA NBI)

Counties (99)

Adair 208 Adams 147 Allamakee 170 Appanoose 159 Audubon 161 Benton 327 Black Hawk 411 Boone 119 Bremer 220 Buchanan 281 Buena Vista 140 Butler 261 Calhoun 171 Carroll 223 Cass 237 Cedar 265 Cerro Gordo 210 Cherokee 223 Chickasaw 268 Clarke 150 Clay 138 Clayton 214 Clinton 325 Crawford 242 Dallas 154 Davis 156 Decatur 178 Delaware 254 Des Moines 156 Dickinson 73 Dubuque 304 Emmet 70 Fayette 288 Floyd 195 Franklin 214 Fremont 133 Greene 150 Grundy 270 Guthrie 236 Hamilton 134 Hancock 128 Hardin 211 Harrison 162 Henry 144 Howard 193 Humboldt 70 Ida 164 Iowa 189 Jackson 209 Jasper 321 Jefferson 142 Johnson 317 Jones 215 Keokuk 152 Kossuth 256 Lee 185 Linn 428 Louisa 134 Lucas 186 Lyon 241 Madison 221 Mahaska 219 Marion 204 Marshall 283 Mills 170 Mitchell 160 Monona 125 Monroe 126 Montgomery 184 Muscatine 127 O'Brien 229 Osceola 176 Page 185 Palo Alto 114 Plymouth 407 Pocahontas 186 Polk 415 Pottawattamie 469 Poweshiek 221 Ringgold 206 Sac 188 Scott 212 Shelby 194 Sioux 429 Story 262 Tama 307 Taylor 220 Union 153 Van Buren 142 Wapello 160 Warren 231 Washington 203 Wayne 163 Webster 179 Winnebago 48 Winneshiek 317 Woodbury 379 Worth 89 Wright 168

Iowa 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 Iowa on the same metric.

WV

West Virginia

16.02% top marginal rate
Structure
Progressive
Burden @ $100K
$7,679

SD

South Dakota

16.24% top marginal rate
Structure
Progressive
Burden @ $100K
$5,905
Selected

IA

Iowa

20.01% top marginal rate
Structure
Progressive
Burden @ $100K
$20,753

VI

Virgin Islands

29.17% top marginal rate
Structure
Progressive
Burden @ $100K
$24

Bridges Needing Most Attention in Iowa

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

270TH STREET

Poor

Over: ROSE BRANCH

071343401, Adams, IA

Built 1976 Load: 2.7 t ADT: 79

LOCAL

Poor

Over: CREEK

078342601, Audubon, IA

Built 1935 Load: 2.7 t ADT: 21

KLINE RD

Poor

Over: MUD CREEK

87-12-15-02-10, Black Hawk, IA

Built 1948 Load: 2.7 t ADT: 11

LOCAL - 700TH

Poor

Over: TRIB TROUBLESOME CREEK

077351402, Cass, IA

Built 1983 Load: 2.7 t ADT: 11

LOCAL - DAYTONA

Poor

Over: BUCK CREEK

077361903, Cass, IA

Built 1980 Load: 2.7 t ADT: 35

100TH ST.

Poor

Over: UNION CREEK

083E20101, Clinton, IA

Built 1900 Load: 2.7 t ADT: 78

All Bridges in Iowa

300 TH

Poor

Over: GREENBRIER CREEK

082311401, Greene, IA

Built 1957 Load: 18.8 t ADT: 15

290 TH / E57

Poor

Over: WILLOW CREEK

082320703, Greene, IA

Built 1953 Load: 18.8 t ADT: 89

320 TH

Poor

Over: STREAM

082322801, Greene, IA

Built 1956 Load: 18.8 t ADT: 11

140 TH

Poor

Over: STREAM

085302701, Greene, IA

Built 1956 Load: 18.8 t ADT: 26

LOCAL

Poor

Over: STREAM

080313303, Guthrie, IA

Built 1973 Load: 18.8 t ADT: 50

WILLOW AVE

Poor

Over: BOHEMIAN CREEK

097110202, Howard, IA

Built 1951 Load: 18.8 t ADT: 1,420

120TH ST

Poor

Over: STREAM

081050901, Johnson, IA

Built 1952 Load: 18.8 t ADT: 30

160TH ST

Poor

Over: BR MILL CR

081052201, Johnson, IA

Built 1955 Load: 18.8 t ADT: 60

LOCAL SECONDARY

Poor

Over: LITTLE SUGAR CREEK

068072104, Lee, IA

Built 1900 Load: 18.8 t ADT: 20

FM

Poor

Over: LITTLE SIOUX RIVER

085440205, Monona, IA

Built 1925 Load: 18.8 t ADT: 159

LOCAL

Poor

Over: TARKIO CREEK TRIB

071381401, Montgomery, IA

Built 1956 Load: 18.8 t ADT: 15

LOCAL

Poor

Over: WAPSINONOC CREEK

078030703, Muscatine, IA

Built 1936 Load: 18.8 t ADT: 176

FM

Poor

Over: SAND CREEK

070280905, Ringgold, IA

Built 1939 Load: 18.8 t ADT: 60

LOCAL

Poor

Over: OTTER CREEK

083142905, Tama, IA

Built 1930 Load: 18.8 t ADT: 29

LOCAL

Poor

Over: CREEK

068080204, Van Buren, IA

Built 1969 Load: 18.8 t ADT: 51

FM

Poor

Over: CREEK

068111810, Van Buren, IA

Built 1955 Load: 18.8 t ADT: 25

LOCAL

Poor

Over: TRIB TO HOLCOMB CREEK

069110303, Van Buren, IA

Built 1976 Load: 18.8 t ADT: 40

LOCAL

Poor

Over: CREEK

070110707, Van Buren, IA

Built 1956 Load: 18.8 t ADT: 50

LOCAL

Poor

Over: STREAM

069161005, Appanoose, IA

Built 1900 Load: 18.9 t ADT: 21

LOCAL

Poor

Over: DD 37

089341102, Calhoun, IA

Built 1960 Load: 18.9 t ADT: 26

LOCAL - 760TH

Poor

Over: WEST NODAWAY CREEK

075343504, Cass, IA

Built 1988 Load: 18.9 t ADT: 11

330TH ST

Poor

Over: STREAM

079043501, Cedar, IA

Built 1930 Load: 18.9 t ADT: 11

LOCAL

Poor

Over: CREEK

097133402, Chickasaw, IA

Built 1970 Load: 18.9 t ADT: 35

FM

Poor

Over: WEST CREEK

073251604, Clarke, IA

Built 1958 Load: 18.9 t ADT: 459

LOCAL

Poor

Over: STREAM

094313601, Palo Alto, IA

Built 1927 Load: 18.9 t ADT: 90

LOCAL

Poor

Over: BRANCH COON CREEK

085141504, Tama, IA

Built 1966 Load: 18.9 t ADT: 39

LOCAL

Poor

Over: SMALL STREAM

071290408, Union, IA

Built 1990 Load: 18.9 t ADT: 5

LOCAL

Poor

Over: SMALL STREAM

089082804, Buchanan, IA

Built 1951 Load: 19.0 t ADT: 15

LOCAL

Poor

Over: FIELD STREAM

083363002, Carroll, IA

Built 1962 Load: 19.0 t ADT: 11

255TH ST

Poor

Over: CROOKED CREEK

080021905, Cedar, IA

Built 1965 Load: 19.0 t ADT: 40

LOCAL 35TH ST

Poor

Over: SMALL STREAM

090193003, Franklin, IA

Built 1936 Load: 19.0 t ADT: 5

RAVEN AVE

Poor

Over: MAYNES CREEK

091201408, Franklin, IA

Built 1955 Load: 19.0 t ADT: 30

LOCAL RD

Poor

Over: BRANCH BLACK HAWK CREEK

088160204, Grundy, IA

Built 1963 Load: 19.0 t ADT: 26

FM

Poor

Over: BEAR CREEK

079311802, Guthrie, IA

Built 1959 Load: 19.0 t ADT: 120

LOCAL

Poor

Over: DRAINAGE DITCH

088242501, Hamilton, IA

Built 1919 Load: 19.0 t ADT: 30

LOCAL

Poor

Over: ODEBOLT CREEK

087402403, Ida, IA

Built 1967 Load: 19.0 t ADT: 2,884

LOCAL ROAD

Poor

Over: CREEK

069062608, Lee, IA

Built 1977 Load: 19.0 t ADT: 15

FM

Poor

Over: OVERFLOW

098430501, Lyon, IA

Built 1969 Load: 19.0 t ADT: 718

LOCAL

Poor

Over: CREEK

085171902, Marshall, IA

Built 1940 Load: 19.0 t ADT: 30

430TH

Poor

Over: CREEK

099162301, Mitchell, IA

Built 1953 Load: 19.0 t ADT: 403

LOCAL

Poor

Over: STREAM

100411403, Osceola, IA

Built 1957 Load: 19.0 t ADT: 41

FM C-43

Poor

Over: BROKEN KETTLE CREEK

091482205, Plymouth, IA

Built 1960 Load: 19.0 t ADT: 159

LOCAL

Poor

Over: LIZARD CREEK DD #164

091313102, Pocahontas, IA

Built 1978 Load: 19.0 t ADT: 30

LOCAL

Poor

Over: SMALL

079161701, Poweshiek, IA

Built 1979 Load: 19.0 t ADT: 90

650TH AVE

Poor

Over: EAST BR INDIAN CREEK

085222702, Story, IA

Built 1922 Load: 19.0 t ADT: 60

140TH ST

Poor

Over: EAST BR INDIAN CREEK

085222901, Story, IA

Built 1924 Load: 19.0 t ADT: 5

520TH AVE

Poor

Over: KEIGLEY BRANCH

085240902, Story, IA

Built 1949 Load: 19.0 t ADT: 34

LOCAL

Poor

Over: WOLF CREEK

087441101, Woodbury, IA

Built 1981 Load: 19.0 t ADT: 20

E35 (200TH ST)

Poor

Over: FIELD STREAM

084363001, Carroll, IA

Built 1946 Load: 19.1 t ADT: 60

CHARLES AVE

Poor

Over: W BR WAPSINONOC CR

079042102, Cedar, IA

Built 1925 Load: 19.1 t ADT: 35

Showing 19,101-19,150 of 20,753 bridges

Related

All states → | National rankings → | Understanding conditions → | Retired SD term explained →
Data sourced from the FHWA National Bridge Inventory (NBI), latest released cycle. See our methodology for details. Retrieved and formatted by PlainBridges.

Disclaimer: This information is provided for informational purposes only and does not constitute professional advice. Data is sourced from the FHWA National Bridge Inventory (NBI). Poor condition is an inspection-record category, not a closure or unsafe-to-cross designation. Consult the bridge owner for current status.

Understanding Bridge Conditions

How FHWA rates bridge condition on a 0-9 scale.

Check Your Daily Bridges

How to look up bridge condition data for bridges on your route.

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

Every figure on PlainBridge 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.