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: SMALL

094471302, Sioux, IA

Built 1978 Load: 34.7 t ADT: 34

LOCAL

Poor

Over: STREAM

078131204, Poweshiek, IA

Built 1965 Load: 34.8 t ADT: 30

LOCAL

Poor

Over: STREAM

081162601, Poweshiek, IA

Built 1953 Load: 34.8 t ADT: 30

LOCAL ROAD

Poor

Over: CREEK

097081903, Winneshiek, IA

Built 1977 Load: 34.8 t ADT: 59

FM

Poor

Over: CAIN CREEK

088340301, Calhoun, IA

Built 1968 Load: 34.9 t ADT: 110

LOCAL - 580TH

Poor

Over: LITTLE CAMP CREEK

077371102, Cass, IA

Built 1981 Load: 35.0 t ADT: 5

150TH ST

Poor

Over: BROKEN KETTLE CREEK

093473601, Plymouth, IA

Built 1952 Load: 35.0 t ADT: 26

LOCAL

Poor

Over: CREEK

087020204, Dubuque, IA

Built 1925 Load: 35.1 t ADT: 30

LOCAL

Poor

Over: N SKUNK RIVER

083202002, Marshall, IA

Built 1917 Load: 35.1 t ADT: 49

FM

Poor

Over: CREEK

084172502, Marshall, IA

Built 1917 Load: 35.1 t ADT: 108

LOCAL

Poor

Over: MINERVA CR

084201002, Marshall, IA

Built 1917 Load: 35.1 t ADT: 21

FM

Poor

Over: WALNUT CREEK

080E11208, Scott, IA

Built 1949 Load: 35.1 t ADT: 1,060

FM

Poor

Over: CRANE CREEK

096113004, Chickasaw, IA

Built 1971 Load: 35.3 t ADT: 275

SAWYER RD

Poor

Over: TRIB TO BUFFALO CREEK

085050407, Linn, IA

Built 1926 Load: 35.3 t ADT: 1,100

LOCAL

Poor

Over: PLEASANT CREEK

077142705, Mahaska, IA

Built 1949 Load: 35.3 t ADT: 15

LOCAL

Poor

Over: CREEK

077E11703, Muscatine, IA

Built 1942 Load: 35.3 t ADT: 21

480TH

Poor

Over: SMALL STREAM

100182601, Mitchell, IA

Built 1984 Load: 35.4 t ADT: 216

FM

Poor

Over: STREAM

068263605, Decatur, IA

Built 1940 Load: 35.5 t ADT: 60

LOCAL

Poor

Over: BEAVER CREEK

083281101, Boone, IA

Built 1920 Load: 35.6 t ADT: 26

LOCAL

Poor

Over: HICKORY CREEK

074201202, Marion, IA

Built 1997 Load: 35.6 t ADT: 15

WALNUT ST

Poor

Over: ABANDON RR

082200903, Marshall, IA

Built 1977 Load: 35.6 t ADT: 689

LOCAL

Poor

Over: BRANCH IOWA RIVER

082140603, Tama, IA

Built 1983 Load: 35.6 t ADT: 11

FM

Poor

Over: WEST 102 RIVER

070352401, Taylor, IA

Built 1985 Load: 35.6 t ADT: 309

LOCAL

Poor

Over: CREEK

086192703, Hardin, IA

Built 1995 Load: 35.7 t ADT: 11

LINCOLN AVE

Poor

Over: BR CRANE CREEK

098133606, Howard, IA

Built 1990 Load: 35.7 t ADT: 25

LOCAL

Poor

Over: DEER CREEK

090292204, Webster, IA

Built 1925 Load: 35.7 t ADT: 81

LOCAL

Poor

Over: BR PRAIRIE CK

082110502, Benton, IA

Built 1958 Load: 35.9 t ADT: 25

FM-H AVE.

Poor

Over: WILLOW CREEK

092412902, Cherokee, IA

Built 1924 Load: 35.9 t ADT: 199

FM

Poor

Over: SKUNK RIVER

086243603, Hamilton, IA

Built 1992 Load: 35.9 t ADT: 459

LOCAL

Poor

Over: SMALL STREAM

080211304, Jasper, IA

Built 1925 Load: 35.9 t ADT: 35

308TH AVE.

Poor

Over: SUGAR CREEK

083E40404, Clinton, IA

Built 1985 Load: 36.0 t ADT: 70

S67 WREN AVE

Poor

Over: STREAM

091193502, Franklin, IA

Built 1962 Load: 36.0 t ADT: 79

OLD IA 77

Poor

Over: RICHLAND CREEK

074102210, Keokuk, IA

Built 1932 Load: 36.1 t ADT: 620

LOCAL

Poor

Over: E FK GRAND RIVER

070291301, Ringgold, IA

Built 1940 Load: 36.2 t ADT: 5

LOCAL

Poor

Over: SMALL STREAM

089090402, Buchanan, IA

Built 1951 Load: 36.3 t ADT: 30

FM

Poor

Over: BEAVER CREEK

089172201, Grundy, IA

Built 1973 Load: 36.3 t ADT: 501

FM

Poor

Over: EAST FORK CROOKED CREEK

073050904, Henry, IA

Built 1970 Load: 36.3 t ADT: 910

FM

Poor

Over: W FK GRAND RIVER

070303203, Ringgold, IA

Built 1979 Load: 36.3 t ADT: 190

FM

Poor

Over: BOYER RIVER

088373301, Sac, IA

Built 1979 Load: 36.3 t ADT: 100

FM

Poor

Over: HINKLE CREEK

085112804, Benton, IA

Built 1988 Load: 36.4 t ADT: 530

FM

Poor

Over: TRIB. OF SQUAW CREEK

085253601, Boone, IA

Built 1920 Load: 36.6 t ADT: 90

FM

Poor

Over: CREEK

086E53004, Jackson, IA

Built 1977 Load: 36.6 t ADT: 120

WAUBEEK RD

Poor

Over: TRIB WAPSIPINICON R

085061403, Linn, IA

Built 1927 Load: 36.6 t ADT: 78

VINE

Poor

Over: DEER CREEK

100192702, Worth, IA

Built 1977 Load: 36.6 t ADT: 59

MALLARD AVE

Poor

Over: DRAINAGE DITCH

100203102, Worth, IA

Built 1973 Load: 36.6 t ADT: 216

FM

Poor

Over: WAPSIPINICON RIVER

082011408, Cedar, IA

Built 1969 Load: 36.7 t ADT: 520

PARKER TRAIL

Poor

Over: SMALL CREEK

079420904, Harrison, IA

Built 1916 Load: 36.7 t ADT: 29

LOCAL

Poor

Over: SMALL STREAM

087433503, Woodbury, IA

Built 1985 Load: 36.8 t ADT: 11

FM

Poor

Over: PRATT CREEK

086112502, Benton, IA

Built 1989 Load: 36.9 t ADT: 540

170TH AVE

Poor

Over: SAND CREEK

088050802, Delaware, IA

Built 1953 Load: 36.9 t ADT: 39

Showing 20,601-20,650 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.