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

Poor

Over: LITTLE WAPSIPINICON RVR

095131601, Chickasaw, IA

Built 1980 Load: 31.9 t ADT: 88

E 92ND ST S

Poor

Over: SMALL

078180306, Jasper, IA

Built 1979 Load: 31.9 t ADT: 35

IOWA AVE

Poor

Over: IOWA RIVER

79060900, Johnson, IA

Built 1916 Load: 31.9 t ADT: 5,400

FM

Poor

Over: CREEK

096132801, Chickasaw, IA

Built 1976 Load: 32.0 t ADT: 88

FM

Poor

Over: LITTLE CEDAR

096153505, Floyd, IA

Built 1967 Load: 32.0 t ADT: 59

180TH ST

Poor

Over: LITTLE TURKEY RIVER

097110601, Howard, IA

Built 1985 Load: 32.0 t ADT: 29

FM

Poor

Over: WEXFORD CREEK

098032506, Allamakee, IA

Built 1970 Load: 32.1 t ADT: 530

FM 160TH AVE

Poor

Over: WILLOW CREEK

095373002, Clay, IA

Built 1962 Load: 32.1 t ADT: 190

LOCAL

Poor

Over: E FK GRAND RIVER

068292701, Ringgold, IA

Built 1961 Load: 32.1 t ADT: 26

LCL-410TH ST

Poor

Over: INDIAN CREEK

072402604, Mills, IA

Built 1950 Load: 32.2 t ADT: 51

FM

Poor

Over: STREAM

069301006, Ringgold, IA

Built 1941 Load: 32.2 t ADT: 71

FM

Poor

Over: OPOSSUM CREEK

084101601, Benton, IA

Built 1959 Load: 32.3 t ADT: 1,090

LOCAL RD

Poor

Over: DRAINAGE DITCH

095121902, Chickasaw, IA

Built 1954 Load: 32.3 t ADT: 2,396

300TH ST.

Poor

Over: QUINN CREEK

095070703, Fayette, IA

Built 1997 Load: 32.3 t ADT: 29

330 TH / E63

Poor

Over: DRAINAGE DITCH 9-13

082323101, Greene, IA

Built 1970 Load: 32.3 t ADT: 379

FM

Poor

Over: PLUM CREEK

098480102, Lyon, IA

Built 1968 Load: 32.3 t ADT: 210

LOCAL

Poor

Over: SMALL STREAM

803037, Shelby, IA

Built 1959 Load: 32.3 t ADT: 35

MAIN ST L43

Poor

Over: BACON CREEK

088410108, Woodbury, IA

Built 1958 Load: 32.3 t ADT: 383

RACINE AVE

Poor

Over: DRAINAGE DITCH

088082304, Buchanan, IA

Built 1953 Load: 32.4 t ADT: 2,671

FM

Poor

Over: LYTLE CREEK

087E20903, Dubuque, IA

Built 1977 Load: 32.4 t ADT: 50

LOCAL

Poor

Over: CREEK

069100606, Van Buren, IA

Built 1964 Load: 32.4 t ADT: 11

FM

Poor

Over: HINKLE CREEK

085113201, Benton, IA

Built 1962 Load: 32.6 t ADT: 570

LOCAL

Poor

Over: IOWAY CREEK

085250902, Boone, IA

Built 1920 Load: 32.6 t ADT: 20

LOCAL

Poor

Over: STREAM

077300101, Adair, IA

Built 1947 Load: 32.7 t ADT: 11

LOCAL

Poor

Over: STREAM

074333639, Adair, IA

Built 1900 Load: 32.7 t ADT: 11

ORANGE AVENUE

Poor

Over: LONZO CREEK

071333402, Adams, IA

Built 1968 Load: 32.7 t ADT: 26

170TH STREET

Poor

Over: MT. ZION BRANCH

072331201, Adams, IA

Built 1965 Load: 32.7 t ADT: 20

QUINCY RD

Poor

Over: WATERWAY

075352701, Cass, IA

Built 1975 Load: 32.7 t ADT: 91

175TH AVE

Poor

Over: STREAM

073260506, Clarke, IA

Built 1976 Load: 32.7 t ADT: 34

FLEETWOOD RD

Poor

Over: BEAR CR

091052206, Clayton, IA

Built 1930 Load: 32.7 t ADT: 589

B AVE.

Poor

Over: BRUCE CREEK

091072502, Fayette, IA

Built 1916 Load: 32.7 t ADT: 88

30TH ST.

Poor

Over: UNAMED CR

091073001, Fayette, IA

Built 1923 Load: 32.7 t ADT: 33

120TH ST.

Poor

Over: ALEXANDER CR

092080801, Fayette, IA

Built 1989 Load: 32.7 t ADT: 33

110TH ST.

Poor

Over: UNNAMED CREEK

092081301, Fayette, IA

Built 1988 Load: 32.7 t ADT: 15

90TH ST.

Poor

Over: SMALL STREAM

092082901, Fayette, IA

Built 1990 Load: 32.7 t ADT: 34

DOGWOOD RD.

Poor

Over: MINK CR

093070904, Fayette, IA

Built 1923 Load: 32.7 t ADT: 39

157TH ST.

Poor

Over: UNNAMED CR

093072103, Fayette, IA

Built 1998 Load: 32.7 t ADT: 29

147TH ST.

Poor

Over: UNAMED CR

093072603, Fayette, IA

Built 1917 Load: 32.7 t ADT: 49

B AVE.

Poor

Over: DEEP CREEK

093073604, Fayette, IA

Built 2000 Load: 32.7 t ADT: 39

152TH ST.

Poor

Over: THE COULEE

093081903, Fayette, IA

Built 1924 Load: 32.7 t ADT: 44

160TH ST

Poor

Over: UNAMED CREEK

093091901, Fayette, IA

Built 1920 Load: 32.7 t ADT: 11

160TH ST

Poor

Over: UNNAMED CREEK

093102001, Fayette, IA

Built 1995 Load: 32.7 t ADT: 20

247TH ST

Poor

Over: HAUGH CREEK

094100503, Fayette, IA

Built 1920 Load: 32.7 t ADT: 33

JELLY RD.

Poor

Over: DRY BR CR

095080404, Fayette, IA

Built 1917 Load: 32.7 t ADT: 20

GRANITE RD.

Poor

Over: NUTTING CREEK

095081208, Fayette, IA

Built 1909 Load: 32.7 t ADT: 44

JUNIPER RD.

Poor

Over: CREEK

095082106, Fayette, IA

Built 1962 Load: 32.7 t ADT: 403

306TH ST

Poor

Over: CREEK

095100405, Fayette, IA

Built 1988 Load: 32.7 t ADT: 29

306TH ST

Poor

Over: SMALL DRY RUN

095100405, Fayette, IA

Built 1988 Load: 32.7 t ADT: 29

J AVE.

Poor

Over: SMALL

091081502, Fayette, IA

Built 1986 Load: 32.7 t ADT: 44

X AVE

Poor

Over: SMALL

091100802, Fayette, IA

Built 1984 Load: 32.7 t ADT: 33

Showing 19,051-19,100 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.