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

OLD IA 102

Poor

Over: BUCKLEY CREEK

077172703, Mahaska, IA

Built 1967 Load: 30.4 t ADT: 2,340

FM

Poor

Over: LITTLE FLOYD RIVER

096420802, O'Brien, IA

Built 1968 Load: 30.4 t ADT: 50

FM

Poor

Over: DD # 77 NO LIZARD CK

091310502, Pocahontas, IA

Built 1973 Load: 30.4 t ADT: 698

FM

Poor

Over: BEAVER CREEK

093321301, Pocahontas, IA

Built 1973 Load: 30.4 t ADT: 369

FM

Poor

Over: DRAINAGE

075380404, Pottawattamie, IA

Built 1964 Load: 30.4 t ADT: 270

FM

Poor

Over: BOYER RIVER

0893722, Sac, IA

Built 1964 Load: 30.4 t ADT: 249

FM

Poor

Over: BRANCH SALT CREEK

083132004, Tama, IA

Built 1970 Load: 30.4 t ADT: 432

FM

Poor

Over: SO BRANCH SALT CREEK

084133202, Tama, IA

Built 1969 Load: 30.4 t ADT: 363

FM

Poor

Over: VILLAGE CREEK

071130904, Wapello, IA

Built 1968 Load: 30.4 t ADT: 250

LOCAL

Poor

Over: MIDDLE AVERY CREEK

073153306, Wapello, IA

Built 1968 Load: 30.4 t ADT: 62

FM

Poor

Over: WOLF CREEK

087442103, Woodbury, IA

Built 1968 Load: 30.4 t ADT: 71

FM

Poor

Over: MUD CREEK

089440701, Woodbury, IA

Built 1969 Load: 30.4 t ADT: 709

FM

Poor

Over: WHISKEY CREEK

089461201, Woodbury, IA

Built 1967 Load: 30.4 t ADT: 628

FISH POND RD

Poor

Over: CREEK

088010304, Dubuque, IA

Built 1997 Load: 30.5 t ADT: 128

FM

Poor

Over: LITTLE CEDAR

096151603, Floyd, IA

Built 1967 Load: 30.5 t ADT: 167

FM

Poor

Over: LITTLE CEDAR CREEK

070072603, Henry, IA

Built 1972 Load: 30.5 t ADT: 650

LOCAL

Poor

Over: BR OF CARRUTHERS CREEK

073200301, Lucas, IA

Built 1900 Load: 30.5 t ADT: 11

FM

Poor

Over: MOSQUITO CK

078022804, Muscatine, IA

Built 1978 Load: 30.5 t ADT: 1,260

LOCAL (LWC)

Poor

Over: STREAM

083112902, Benton, IA

Built 1977 Load: 30.6 t ADT: 34

MARQUIS RD

Poor

Over: SHELL ROCK RIV OVERFLOW

90-14-04-07-10, Black Hawk, IA

Built 1992 Load: 30.6 t ADT: 207

FM

Poor

Over: MC CLURE CREEK

091150802, Butler, IA

Built 1970 Load: 30.6 t ADT: 470

FM

Poor

Over: SMALL STREAM

091171702, Butler, IA

Built 1970 Load: 30.6 t ADT: 373

FM-530TH ST

Poor

Over: W FORK LITTLE SIOUX

092423501, Cherokee, IA

Built 1968 Load: 30.6 t ADT: 898

LOCAL

Poor

Over: CHARITON CR

071242804, Clarke, IA

Built 1986 Load: 30.6 t ADT: 20

FM

Poor

Over: OTTER CREEK

073242002, Clarke, IA

Built 1969 Load: 30.6 t ADT: 319

LOCAL

Poor

Over: CREEK

094151302, Floyd, IA

Built 1970 Load: 30.6 t ADT: 39

LOCAL ROAD

Poor

Over: BRANCH OF WOLF CREEK

086172901, Grundy, IA

Built 1976 Load: 30.6 t ADT: 11

FM

Poor

Over: BEAVER CREEK

088203403, Hardin, IA

Built 1967 Load: 30.6 t ADT: 334

FM

Poor

Over: SILVER CREEK

088391702, Ida, IA

Built 1969 Load: 30.6 t ADT: 589

FM

Poor

Over: BATTLE CREEK

088412504, Ida, IA

Built 1969 Load: 30.6 t ADT: 499

FM

Poor

Over: ENGLISH CREEK

075180406, Marion, IA

Built 1975 Load: 30.6 t ADT: 2,640

FM

Poor

Over: LITTLE CEDAR CREEK

090341002, Pocahontas, IA

Built 1968 Load: 30.6 t ADT: 658

FM

Poor

Over: PILOT CREEK

092310407, Pocahontas, IA

Built 1975 Load: 30.6 t ADT: 509

236TH AVE

Poor

Over: SILVER CREEK

100092416, Winneshiek, IA

Built 1928 Load: 30.6 t ADT: 187

FM

Poor

Over: PRATT CREEK

086113602, Benton, IA

Built 1956 Load: 30.7 t ADT: 540

LOCAL

Poor

Over: MILLER CREEK

078092302, Iowa, IA

Built 1900 Load: 30.7 t ADT: 110

FM

Poor

Over: BEAR CREEK

080182401, Jasper, IA

Built 1914 Load: 30.7 t ADT: 45

LOCAL

Poor

Over: CHERRY CREEK

080190703, Jasper, IA

Built 1927 Load: 30.7 t ADT: 30

LOCAL

Poor

Over: SMALL STREAM

080201802, Jasper, IA

Built 1917 Load: 30.7 t ADT: 51

W 130TH ST N

Poor

Over: SMALL STREAM

080210404, Jasper, IA

Built 1925 Load: 30.7 t ADT: 21

LOCAL

Poor

Over: BRANCH SNIPE CREEK

082192702, Marshall, IA

Built 1920 Load: 30.7 t ADT: 11

LOCAL

Poor

Over: LINN CREEK

083190401, Marshall, IA

Built 1916 Load: 30.7 t ADT: 21

LOCAL

Poor

Over: CREEK

083190503, Marshall, IA

Built 1918 Load: 30.7 t ADT: 35

LOCAL

Poor

Over: BRANCH NORTH TIMBER CRK

083202401, Marshall, IA

Built 1924 Load: 30.7 t ADT: 41

FM

Poor

Over: CEDAR RIVER

078033601, Muscatine, IA

Built 1966 Load: 30.7 t ADT: 990

LOCAL SEC RD

Poor

Over: WILLOW CR

094400203, O'Brien, IA

Built 1919 Load: 30.7 t ADT: 26

LOCAL

Poor

Over: SKILLET CREEK

086281104, Webster, IA

Built 1919 Load: 30.7 t ADT: 46

WINSLOW RD

Poor

Over: TRIB W FORK CEDAR RIVER

90-14-08-03-10, Black Hawk, IA

Built 1966 Load: 30.8 t ADT: 255

FM

Poor

Over: SOUTH CHEQUEST CREEK

069120802, Davis, IA

Built 1981 Load: 30.8 t ADT: 310

FM

Poor

Over: CREEK

088023201, Dubuque, IA

Built 1962 Load: 30.8 t ADT: 490

Showing 18,951-19,000 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.