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: BRANCH OF MAPLE

091380801, Buena Vista, IA

Built 1978 Load: 33.0 t ADT: 30

FM

Poor

Over: CREEK

092362201, Buena Vista, IA

Built 1976 Load: 33.0 t ADT: 249

FM

Poor

Over: BROOKS CREEK

092380101, Buena Vista, IA

Built 1974 Load: 33.0 t ADT: 100

FM

Poor

Over: CEDAR CREEK

087310201, Calhoun, IA

Built 1970 Load: 33.0 t ADT: 71

FM

Poor

Over: CEDAR CREEK

087311901, Calhoun, IA

Built 1971 Load: 33.0 t ADT: 150

FM - 690TH

Poor

Over: JIM CREEK

076352204, Cass, IA

Built 1971 Load: 33.0 t ADT: 329

FM

Poor

Over: BACKWATER (PUMP STATION)

070022105, Des Moines, IA

Built 1972 Load: 33.0 t ADT: 240

J AVE / P14

Poor

Over: GREENBRIER CREEK

082310302, Greene, IA

Built 1971 Load: 33.0 t ADT: 190

FM

Poor

Over: CREEK

088202904, Hardin, IA

Built 1973 Load: 33.0 t ADT: 108

LOCAL

Poor

Over: STREAM

084E60206, Jackson, IA

Built 1986 Load: 33.0 t ADT: 50

FM

Poor

Over: WEST RAT CREEK

098430102, Lyon, IA

Built 1965 Load: 33.0 t ADT: 230

FM

Poor

Over: BR BIG CEDAR CK DD#21

092331801, Pocahontas, IA

Built 1975 Load: 33.0 t ADT: 230

FM

Poor

Over: SMALL STREAM

087361301, Sac, IA

Built 1977 Load: 33.0 t ADT: 110

FM

Poor

Over: SMALL STREAM

086152401, Tama, IA

Built 1981 Load: 33.0 t ADT: 216

FM

Poor

Over: HARDIN CREEK

087300502, Webster, IA

Built 1973 Load: 33.0 t ADT: 1,446

FM

Poor

Over: DD

087301702, Webster, IA

Built 1973 Load: 33.0 t ADT: 1,446

FM

Poor

Over: DD NO 70

087301901, Webster, IA

Built 1974 Load: 33.0 t ADT: 240

FM

Poor

Over: DD

087303202, Webster, IA

Built 1973 Load: 33.0 t ADT: 1,287

FM

Poor

Over: DD NO 4

089271001, Webster, IA

Built 1974 Load: 33.0 t ADT: 559

FM

Poor

Over: DD NO 247

090283404, Webster, IA

Built 1974 Load: 33.0 t ADT: 2,284

CENTRAL AVE N

Poor

Over: SHELLROCK RIVER

000000000, Worth, IA

Built 1950 Load: 33.0 t ADT: 1,868

LOCAL

Poor

Over: LAKE CREEK W BR

087332701, Calhoun, IA

Built 1900 Load: 33.1 t ADT: 11

FM

Poor

Over: NORTH FABIUS CREEK

068152605, Davis, IA

Built 1970 Load: 33.1 t ADT: 140

FM

Poor

Over: MINERVA CREEK

086213003, Hardin, IA

Built 1972 Load: 33.1 t ADT: 550

FM 520TH ST

Poor

Over: PECHMAN CREEK

078062403, Johnson, IA

Built 1974 Load: 33.1 t ADT: 880

FM

Poor

Over: STREAM

069291701, Ringgold, IA

Built 1953 Load: 33.1 t ADT: 170

LOCAL F AVE

Poor

Over: FOUR MILE CREEK

093421302, Cherokee, IA

Built 1924 Load: 33.2 t ADT: 45

FM

Poor

Over: LITTLE SIOUX

099372901, Dickinson, IA

Built 1969 Load: 33.2 t ADT: 319

BUSH RD.

Poor

Over: BRUSH CREEK

093073503, Fayette, IA

Built 1957 Load: 33.2 t ADT: 275

LOCAL

Poor

Over: CREEK

084172812, Marshall, IA

Built 1916 Load: 33.2 t ADT: 123

MILLERS PATH

Poor

Over: STREAM

086430906, Woodbury, IA

Built 1947 Load: 33.2 t ADT: 50

FM

Poor

Over: PRAIRIE CREEK

082101402, Benton, IA

Built 1961 Load: 33.3 t ADT: 766

FM

Poor

Over: LOST BRANCH CREEK

071203008, Lucas, IA

Built 1984 Load: 33.3 t ADT: 50

FM

Poor

Over: LITTLE OCHEYEDAN RIVER

098402402, Osceola, IA

Built 1986 Load: 33.3 t ADT: 350

240TH STREET

Poor

Over: BUCHANAN CREEK

068362401, Page, IA

Built 1986 Load: 33.3 t ADT: 34

170TH STY

Poor

Over: UNNAMED CREEK

093101301, Fayette, IA

Built 1949 Load: 33.4 t ADT: 15

FM

Poor

Over: E NISHNABOTNA RIVER

074383601, Pottawattamie, IA

Built 1958 Load: 33.4 t ADT: 60

190TH ST

Poor

Over: WAPSIPINICON RIVER

092111901, Bremer, IA

Built 1976 Load: 33.5 t ADT: 727

FM

Poor

Over: FLINT RIVER

071042204, Des Moines, IA

Built 1974 Load: 33.5 t ADT: 670

FM THRUSH AVE

Poor

Over: MAYNES CREEK

091191702, Franklin, IA

Built 1971 Load: 33.5 t ADT: 236

F AVE NORTHWEST

Poor

Over: CEDAR RIVER

000000000, Linn, IA

Built 1979 Load: 33.5 t ADT: 2,193

K53 DOGWOOD AVE

Poor

Over: MCCANDLESS CLEGHORN

085462402, Monona, IA

Built 1970 Load: 33.5 t ADT: 20

SE 5TH ST

Poor

Over: YEADER CREEK

078242700, Polk, IA

Built 1976 Load: 33.6 t ADT: 4,717

LOCAL LEGNO

Poor

Over: CREEK

099082404, Winneshiek, IA

Built 1913 Load: 33.6 t ADT: 11

FREEMAN AVE

Poor

Over: SMALL STREAM

088102602, Buchanan, IA

Built 1950 Load: 33.7 t ADT: 21

FM 340TH ST

Poor

Over: LITTLE SIOUX RIVER

096371103, Clay, IA

Built 1963 Load: 33.7 t ADT: 2,573

W MT VERNON RD

Poor

Over: TRIB TO CEDAR RIVER

90-13-28-01-20, Black Hawk, IA

Built 1940 Load: 33.8 t ADT: 25

LOCAL

Poor

Over: SMALL STREAM

084E41004, Jackson, IA

Built 1986 Load: 33.8 t ADT: 26

LOCAL

Poor

Over: NO LIZARD CK DD #168

091312301, Pocahontas, IA

Built 1960 Load: 33.8 t ADT: 50

E66

Poor

Over: SALT CREEK

082132403, Tama, IA

Built 1976 Load: 33.9 t ADT: 638

Showing 19,151-19,200 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.