State profile · Above national median SD

Iowa bridge safety

Condition ratings, load ratings, and structural-deficiency data for every public highway bridge in Iowa — drawn straight from the FHWA National Bridge Inventory.

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

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 rated 0-4

Structurally Deficient

20.0%

4,153 bridges flagged for repair priority

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 — Structurally deficient share 66.7%
National avg

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

Condition Distribution

Bridge inventory deck-condition mix — Iowa (FHWA NBI)

Iowa36.534476943092564%38.39444899532597%20.011564593070883%20.011564593070883%GoodFairPoorStructurally Deficient
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 on the structurally deficient leaderboard (lower share = better)

States are ranked by share of bridges flagged structurally deficient — the FHWA classification for any span where deck, superstructure, or substructure carries a condition rating of 4 or below. Lower percentages indicate stronger maintenance funding and inspection follow-through. States here sit immediately above and below Iowa on the same metric.

54

West Virginia

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

46

South Dakota

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

19

Iowa

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

78

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 composite NBI rating. Each is inspected at least every 24 months.

270TH STREET

Structurally Deficient

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

Structurally Deficient

Over: MUD CREEK

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

Built 1948 Load: 2.7 t ADT: 11

LOCAL - 700TH

Structurally Deficient

Over: TRIB TROUBLESOME CREEK

077351402, Cass, IA

Built 1983 Load: 2.7 t ADT: 11

LOCAL - DAYTONA

Structurally Deficient

Over: BUCK CREEK

077361903, Cass, IA

Built 1980 Load: 2.7 t ADT: 35

100TH ST.

Structurally Deficient

Over: UNION CREEK

083E20101, Clinton, IA

Built 1900 Load: 2.7 t ADT: 78

All Bridges in Iowa

SB US 61

Fair

Over: WAPSIPINICON OVERFLOW

2.8 miles S of U.S.30, Clinton, IA

Built 1981 Load: 19.2 t ADT: 8,800

LOCAL

Fair

Over: W FK W NISHNABOTNA RVR

082373602, Crawford, IA

Built 1964 Load: 19.2 t ADT: 11

LOCAL

Fair

Over: PARADISE CREEK

083401102, Crawford, IA

Built 1978 Load: 19.2 t ADT: 30

S 68TH AVE E

Fair

Over: ELK CREEK

079183303, Jasper, IA

Built 1933 Load: 19.2 t ADT: 50

S 32ND AVE W

Fair

Over: SMALL STREAM

079190803, Jasper, IA

Built 1990 Load: 19.2 t ADT: 82

FM

Fair

Over: STREAM

076121501, Keokuk, IA

Built 1996 Load: 19.2 t ADT: 90

LOC 320TH ST

Fair

Over: BLACK CAT CREEK

097301601, Kossuth, IA

Built 1989 Load: 19.2 t ADT: 30

FM

Fair

Over: WATERWAY

074263503, Madison, IA

Built 1949 Load: 19.2 t ADT: 259

IA 23

Fair

Over: CEDAR CREEK

0.6 mi S. of Jct. SR T-67, Mahaska, IA

Built 1969 Load: 19.2 t ADT: 2,130

VIRGINIA DR

Fair

Over: STREAM

074182904, Marion, IA

Built 1968 Load: 19.2 t

LOCAL

Fair

Over: SMALL STREAM

074181406, Marion, IA

Built 1984 Load: 19.2 t ADT: 11

LOCAL

Fair

Over: CREEK

085170901, Marshall, IA

Built 1949 Load: 19.2 t ADT: 20

LOCAL ROAD

Fair

Over: TARKIO CREEK

071370401, Montgomery, IA

Built 1961 Load: 19.2 t ADT: 29

LOCAL ROAD

Fair

Over: LOCAL CREEK

072360102, Montgomery, IA

Built 1998 Load: 19.2 t ADT: 15

FM

Fair

Over: TARKIO CREEK

073372801, Montgomery, IA

Built 1959 Load: 19.2 t ADT: 45

LOCAL

Fair

Over: STREAM

098412602, Osceola, IA

Built 1950 Load: 19.2 t ADT: 11

FM

Fair

Over: DRAINAGE DITCH #64

100393302, Osceola, IA

Built 1947 Load: 19.2 t ADT: 190

LOCAL

Fair

Over: OTTER CREEK

100423401, Osceola, IA

Built 1949 Load: 19.2 t ADT: 26

110TH ST

Fair

Over: KEG CREEK

079391801, Shelby, IA

Built 1954 Load: 19.2 t ADT: 15

LOCAL

Fair

Over: MOSER CREEK

081391601, Shelby, IA

Built 1960 Load: 19.2 t ADT: 11

FM

Fair

Over: PLATTE RIVER

068321003, Taylor, IA

Built 1945 Load: 19.2 t ADT: 50

LOCAL

Fair

Over: CREEK

069342301, Taylor, IA

Built 1998 Load: 19.2 t ADT: 50

LOCAL

Fair

Over: TWELVE MILE CREEK

071290202, Union, IA

Built 1970 Load: 19.2 t ADT: 46

FM

Fair

Over: CREEK

068102206, Van Buren, IA

Built 1954 Load: 19.2 t ADT: 70

LOCAL

Fair

Over: SMALL

071143305, Wapello, IA

Built 1979 Load: 19.2 t ADT: 41

LOCAL ROAD

Fair

Over: CAMP CREEK

077072004, Washington, IA

Built 2007 Load: 19.2 t ADT: 11

LOCAL

Fair

Over: BUCK CREEK

078362801, Audubon, IA

Built 1975 Load: 19.3 t ADT: 15

LOCAL

Fair

Over: E NISHNABOTNA RIVER

081350202, Audubon, IA

Built 1940 Load: 19.3 t ADT: 40

LOCAL

Fair

Over: TRIB DES MOINES RIVER

082263206, Boone, IA

Built 1900 Load: 19.3 t ADT: 50

LOCAL

Fair

Over: SMALL STREAM

091172202, Butler, IA

Built 1900 Load: 19.3 t ADT: 30

LOCAL

Fair

Over: MIDDLE RACCOON RIVER

084343507, Carroll, IA

Built 1963 Load: 19.3 t ADT: 50

FM

Fair

Over: FIELD STREAM

084360102, Carroll, IA

Built 1936 Load: 19.3 t ADT: 40

LOCAL

Fair

Over: LITTLE ELKHORN CR

079012802, Cedar, IA

Built 2002 Load: 19.3 t ADT: 26

LOCAL

Fair

Over: SMALL STREAM

084380804, Crawford, IA

Built 1953 Load: 19.3 t ADT: 41

W 128TH ST S

Fair

Over: SMALL STREAM

079210406, Jasper, IA

Built 1991 Load: 19.3 t ADT: 90

LOCAL

Fair

Over: SMALL

066070206, Lee, IA

Built 1930 Load: 19.3 t ADT: 40

LOCAL

Fair

Over: LITTLE WHITEBREAST CREEK

072211505, Lucas, IA

Built 1985 Load: 19.3 t ADT: 16

LOCAL

Fair

Over: DR DISTRICT #11

100413501, Osceola, IA

Built 1934 Load: 19.3 t ADT: 26

260TH ST

Fair

Over: DRAINAGE DITCH 13

083233003, Story, IA

Built 1968 Load: 19.3 t ADT: 50

LOCAL

Fair

Over: BRUSHY CREEK

068353603, Taylor, IA

Built 1959 Load: 19.3 t ADT: 20

LOCAL ROAD

Fair

Over: CREEK

097091001, Winneshiek, IA

Built 1971 Load: 19.3 t ADT: 44

220TH ST

Fair

Over: TURKEY RIVER

097100303, Winneshiek, IA

Built 1900 Load: 19.3 t ADT: 33

LOCAL

Fair

Over: MARVEL CREEK

075311302, Adair, IA

Built 1985 Load: 19.4 t ADT: 41

FM

Fair

Over: BUFFALO CREEK

089081301, Buchanan, IA

Built 1962 Load: 19.4 t ADT: 88

LOC 110TH ST

Fair

Over: SMALL STREAM

090090701, Buchanan, IA

Built 1963 Load: 19.4 t ADT: 73

COUNTY ROAD

Fair

Over: BRANCH PANTHER CREEK

079280903, Dallas, IA

Built 1925 Load: 19.4 t ADT: 21

FM

Fair

Over: BRUSH CREEK

070140304, Davis, IA

Built 1965 Load: 19.4 t ADT: 60

FM

Fair

Over: STREAM

070152106, Davis, IA

Built 1974 Load: 19.4 t ADT: 35

FM 300TH ST

Fair

Over: SMALL STREAM

087061701, Delaware, IA

Built 1978 Load: 19.4 t ADT: 324

FM SHERWOOD RD

Fair

Over: SMALL STREAM

88 03 17 03, Delaware, IA

Built 2011 Load: 19.4 t ADT: 39

Showing 2,401-2,450 of 20,753 bridges

Related

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

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). A "structurally deficient" rating is a repair-priority signal, not a closure or unsafe-to-cross designation. Consult a qualified civil engineer before making decisions based on this data.

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.