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

LOCAL

Structurally Deficient

Over: DD 20

088322402, Calhoun, IA

Built 1948 Load: 18.5 t ADT: 26

FM - 690TH

Structurally Deficient

Over: TROUBLESOME CREEK

077351502, Cass, IA

Built 1960 Load: 18.5 t ADT: 210

125TH ST

Structurally Deficient

Over: SMALL STREAM

081431603, Harrison, IA

Built 1960 Load: 18.5 t ADT: 5

LOCAL

Structurally Deficient

Over: DD 175

096333401, Palo Alto, IA

Built 1926 Load: 18.5 t ADT: 21

MAIN ST

Structurally Deficient

Over: TRIB DES MOINES RIVER

070110803, Van Buren, IA

Built 1965 Load: 18.5 t ADT: 5

LOCAL ROAD

Structurally Deficient

Over: CREEK

099081105, Winneshiek, IA

Built 1900 Load: 18.5 t ADT: 11

LOCAL

Structurally Deficient

Over: EAST BOYER RIVER

083380806, Crawford, IA

Built 1967 Load: 18.6 t ADT: 125

LOCAL

Structurally Deficient

Over: BLACK HAWK CREEK

087152102, Grundy, IA

Built 1946 Load: 18.6 t ADT: 59

FM

Structurally Deficient

Over: BRUSHY CREEK

088272302, Webster, IA

Built 1900 Load: 18.6 t ADT: 30

LOCAL

Structurally Deficient

Over: DRAINAGE

071373202, Montgomery, IA

Built 1952 Load: 18.7 t ADT: 15

LOCAL

Structurally Deficient

Over: TRIB CHEQUEST CREEK

069111303, Van Buren, IA

Built 1955 Load: 18.7 t ADT: 5

G-58

Structurally Deficient

Over: OTTER CREEK

075232209, Warren, IA

Built 1951 Load: 18.7 t ADT: 996

FM

Structurally Deficient

Over: BEAVER CREEK

096143001, Chickasaw, IA

Built 1961 Load: 18.8 t ADT: 44

WILLOW AVE

Structurally Deficient

Over: BOHEMIAN CREEK

097110202, Howard, IA

Built 1951 Load: 18.8 t ADT: 1,420

LOCAL SECONDARY

Structurally Deficient

Over: LITTLE SUGAR CREEK

068072104, Lee, IA

Built 1900 Load: 18.8 t ADT: 20

LOCAL

Structurally Deficient

Over: TARKIO CREEK TRIB

071381401, Montgomery, IA

Built 1956 Load: 18.8 t ADT: 15

FM

Structurally Deficient

Over: SAND CREEK

070280905, Ringgold, IA

Built 1939 Load: 18.8 t ADT: 60

LOCAL

Structurally Deficient

Over: TRIB TO HOLCOMB CREEK

069110303, Van Buren, IA

Built 1976 Load: 18.8 t ADT: 40

LOCAL

Structurally Deficient

Over: BRANCH COON CREEK

085141504, Tama, IA

Built 1966 Load: 18.9 t ADT: 39

LOCAL

Structurally Deficient

Over: SMALL STREAM

071290408, Union, IA

Built 1990 Load: 18.9 t ADT: 5

LOCAL 35TH ST

Structurally Deficient

Over: SMALL STREAM

090193003, Franklin, IA

Built 1936 Load: 19.0 t ADT: 5

RAVEN AVE

Structurally Deficient

Over: MAYNES CREEK

091201408, Franklin, IA

Built 1955 Load: 19.0 t ADT: 30

LOCAL RD

Structurally Deficient

Over: BRANCH BLACK HAWK CREEK

088160204, Grundy, IA

Built 1963 Load: 19.0 t ADT: 26

LOCAL

Structurally Deficient

Over: DRAINAGE DITCH

088242501, Hamilton, IA

Built 1919 Load: 19.0 t ADT: 30

LOCAL ROAD

Structurally Deficient

Over: CREEK

069062608, Lee, IA

Built 1977 Load: 19.0 t ADT: 15

430TH

Structurally Deficient

Over: CREEK

099162301, Mitchell, IA

Built 1953 Load: 19.0 t ADT: 403

CHARLES AVE

Structurally Deficient

Over: W BR WAPSINONOC CR

079042102, Cedar, IA

Built 1925 Load: 19.1 t ADT: 35

LOCAL

Structurally Deficient

Over: SIMPSON CREEK

095111704, Chickasaw, IA

Built 1965 Load: 19.1 t ADT: 62

LOCAL

Structurally Deficient

Over: CATFISH CREEK

088E20903, Dubuque, IA

Built 1980 Load: 19.1 t ADT: 530

FM

Structurally Deficient

Over: TIMBER CREEK

083182102, Marshall, IA

Built 1947 Load: 19.1 t ADT: 79

LOCAL

Structurally Deficient

Over: DEER CREEK

090290914, Webster, IA

Built 1900 Load: 19.2 t ADT: 35

CEMETARY RD

Structurally Deficient

Over: CEDAR RIVER

079031206, Cedar, IA

Built 1930 Load: 19.3 t ADT: 72

230TH ST

Structurally Deficient

Over: STREAM

080011201, Cedar, IA

Built 1950 Load: 19.3 t ADT: 71

LOCAL

Structurally Deficient

Over: WRIGHT CREEK

088422302, Woodbury, IA

Built 1950 Load: 19.3 t ADT: 11

LOCAL

Structurally Deficient

Over: SMALL STREAM

081180302, Jasper, IA

Built 1976 Load: 19.4 t ADT: 5

130TH ST

Structurally Deficient

Over: DRAINAGE

093451901, Plymouth, IA

Built 1961 Load: 19.4 t ADT: 20

LOCAL

Structurally Deficient

Over: SUGAR CREEK

084160701, Tama, IA

Built 1917 Load: 19.6 t ADT: 20

LOCAL

Structurally Deficient

Over: BRUSH CREEK

071152502, Wapello, IA

Built 1930 Load: 19.6 t ADT: 16

LOCAL

Structurally Deficient

Over: SMALL STREAM

090181902, Butler, IA

Built 1949 Load: 19.7 t ADT: 91

LOCAL-520TH ST.

Structurally Deficient

Over: FIDDLE CREEK

092422901, Cherokee, IA

Built 1924 Load: 19.7 t ADT: 34

PLEASANT AVE

Structurally Deficient

Over: DRAINAGE DITCH

099121004, Howard, IA

Built 1970 Load: 19.7 t ADT: 31

LOCAL

Structurally Deficient

Over: LITTLE BEAVER CREEK

082272802, Boone, IA

Built 1900 Load: 19.9 t ADT: 26

CO. RD. D-35

Structurally Deficient

Over: BEAVER CREEK

088203301, Hardin, IA

Built 1960 Load: 19.9 t ADT: 250

LOCAL

Structurally Deficient

Over: DAVISONS CREEK

083171404, Marshall, IA

Built 1978 Load: 19.9 t ADT: 20

LOCAL

Structurally Deficient

Over: EAGLE CREEK

092252802, Wright, IA

Built 1979 Load: 19.9 t ADT: 11

LOCAL

Structurally Deficient

Over: DD #10

093253602, Wright, IA

Built 1968 Load: 19.9 t ADT: 21

LOCAL

Structurally Deficient

Over: STREAM

084E52806, Jackson, IA

Built 1970 Load: 20.0 t ADT: 50

LOCAL

Structurally Deficient

Over: DRAINAGE DITCH

071161403, Monroe, IA

Built 1974 Load: 20.0 t ADT: 11

LOCAL

Structurally Deficient

Over: BRANCH WOLF CREEK

086162502, Tama, IA

Built 1963 Load: 20.0 t ADT: 29

LOCAL

Structurally Deficient

Over: SMALL STREAM

072310401, Union, IA

Built 1900 Load: 20.0 t ADT: 30

Showing 20,551-20,600 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.