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

LOCAL

Poor

Over: TRIB TARKIO

072372804, Montgomery, IA

Built 1955 Load: 10.4 t ADT: 5

LOCAL

Poor

Over: EAST 102 RIVER

068330809, Taylor, IA

Built 1971 Load: 10.4 t ADT: 20

LOCAL

Poor

Over: BRANCH EAST PLATTE

071301905, Union, IA

Built 1978 Load: 10.4 t ADT: 11

LOCAL

Poor

Over: BRANCH DES MOINES RIVER

073152103, Wapello, IA

Built 1930 Load: 10.4 t ADT: 62

LOCAL

Poor

Over: STREAM

087442403, Woodbury, IA

Built 1950 Load: 10.4 t ADT: 5

LOCAL

Poor

Over: WRIGHT CREEK

088433603, Woodbury, IA

Built 1900 Load: 10.4 t ADT: 20

160TH ST

Poor

Over: BEAVER CREEK

084280401, Boone, IA

Built 1915 Load: 10.5 t ADT: 5

LOCAL-490TH ST

Poor

Over: MAPLE RIVER

092391201, Cherokee, IA

Built 1900 Load: 10.5 t ADT: 40

FM

Poor

Over: SOAP CREEK

070131204, Davis, IA

Built 1956 Load: 10.5 t ADT: 640

LOCAL

Poor

Over: MIDDLE RIVER

078322602, Guthrie, IA

Built 1930 Load: 10.5 t ADT: 60

LOCAL

Poor

Over: IOWAY CREEK

086253201, Hamilton, IA

Built 1917 Load: 10.5 t ADT: 45

1280 HILL AVE

Poor

Over: DD #159

094252002, Hancock, IA

Built 1969 Load: 10.5 t ADT: 31

LOCAL ROAD

Poor

Over: BRANCH SUGAR CREEK

073072807, Henry, IA

Built 1922 Load: 10.5 t ADT: 26

LOCAL

Poor

Over: STREAM

076150601, Mahaska, IA

Built 1950 Load: 10.5 t ADT: 140

300TH ST

Poor

Over: JOHN'S CREEK

090441301, Plymouth, IA

Built 1900 Load: 10.5 t ADT: 26

FM

Poor

Over: UNNAMED CREEK

086371502, Sac, IA

Built 1955 Load: 10.5 t ADT: 60

LOCAL

Poor

Over: SMALL

069350401, Taylor, IA

Built 1979 Load: 10.5 t ADT: 5

LOCAL

Poor

Over: CREEK

079361108, Audubon, IA

Built 1956 Load: 10.6 t ADT: 26

LOCAL - QUINCY

Poor

Over: WATERWAY

075342801, Cass, IA

Built 1967 Load: 10.6 t ADT: 30

LOCAL

Poor

Over: CHARITON CR

071243004, Clarke, IA

Built 1960 Load: 10.6 t ADT: 15

LOCAL

Poor

Over: SMALL STREAM

072242502, Clarke, IA

Built 1900 Load: 10.6 t ADT: 11

1550 210TH ST

Poor

Over: DRAINAGE DITCH 6

095240901, Hancock, IA

Built 1968 Load: 10.6 t ADT: 259

TEMPLE AVE

Poor

Over: SMALL STREAM

078170303, Jasper, IA

Built 1974 Load: 10.6 t ADT: 80

LOCAL

Poor

Over: ENGLISH CREEK

073212401, Lucas, IA

Built 1954 Load: 10.6 t ADT: 11

LOCAL

Poor

Over: DRAINAGE

075141808, Mahaska, IA

Built 1960 Load: 10.6 t ADT: 60

260TH

Poor

Over: JOHN'S CREEK

091442601, Plymouth, IA

Built 1966 Load: 10.6 t ADT: 11

LOCAL

Poor

Over: SOUTH RIVER

073260704, Clarke, IA

Built 1983 Load: 10.7 t ADT: 5

LOCAL

Poor

Over: W FK W NISHNABOTNA RIVER

082370602, Crawford, IA

Built 1949 Load: 10.7 t ADT: 35

LOCAL

Poor

Over: STREAM

067250603, Decatur, IA

Built 1966 Load: 10.7 t ADT: 11

LOCAL

Poor

Over: SMALL STREAM

079101307, Iowa, IA

Built 1984 Load: 10.7 t ADT: 71

FM

Poor

Over: MAQUOKETA RIVER

084E10104, Jackson, IA

Built 1927 Load: 10.7 t ADT: 50

LOCAL

Poor

Over: DRAINAGE

076280904, Madison, IA

Built 1939 Load: 10.7 t ADT: 34

170TH ST

Poor

Over: DRAINAGE

092460801, Plymouth, IA

Built 1900 Load: 10.7 t ADT: 34

LOCAL

Poor

Over: N LIZARD CREEK

093330901, Pocahontas, IA

Built 1916 Load: 10.7 t ADT: 11

LOCAL

Poor

Over: CREEK

067320304, Taylor, IA

Built 1961 Load: 10.7 t ADT: 5

LOCAL ROAD

Poor

Over: FLANK CREEK

075223301, Warren, IA

Built 1965 Load: 10.7 t ADT: 30

LOCAL ROAD

Poor

Over: BRANCH OTTER CREEK

075230802, Warren, IA

Built 1970 Load: 10.7 t ADT: 288

LOCAL

Poor

Over: STREAM

067182304, Appanoose, IA

Built 1900 Load: 10.8 t ADT: 21

172ND ST

Poor

Over: STREAM

094050903, Clayton, IA

Built 1916 Load: 10.8 t ADT: 16

LOCAL

Poor

Over: STREAM

078330103, Guthrie, IA

Built 1930 Load: 10.8 t ADT: 5

LOCAL

Poor

Over: TILTON CREEK

088223102, Hardin, IA

Built 1981 Load: 10.8 t ADT: 26

JASPER TRAIL

Poor

Over: SMALL CREEK

079441103, Harrison, IA

Built 1900 Load: 10.8 t ADT: 50

FM LOU FALL RD

Poor

Over: BR IOWA RIVER

081072103, Johnson, IA

Built 1956 Load: 10.8 t ADT: 265

LOCAL

Poor

Over: LINN CREEK

084202502, Marshall, IA

Built 1919 Load: 10.8 t ADT: 30

LOCAL

Poor

Over: LOCAL STREAM

082432208, Monona, IA

Built 1900 Load: 10.8 t ADT: 11

310TH ST

Poor

Over: DRY BRANCH

090441901, Plymouth, IA

Built 1941 Load: 10.8 t ADT: 26

FM K-42

Poor

Over: CARTER CREEK

090460202, Plymouth, IA

Built 1941 Load: 10.8 t ADT: 190

LOCAL

Poor

Over: DEEP CREEK

093431001, Plymouth, IA

Built 1941 Load: 10.8 t ADT: 11

LOCAL

Poor

Over: STREAM

071302401, Union, IA

Built 1977 Load: 10.8 t ADT: 41

FM

Poor

Over: NORTH RIVER

077242002, Warren, IA

Built 1960 Load: 10.8 t ADT: 1,714

Showing 17,701-17,750 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.