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

190TH ST

Poor

Over: BUCK CREEK

092112103, Bremer, IA

Built 1976 Load: 30.0 t ADT: 727

FM

Poor

Over: LANDPHERE CREEK

091153204, Butler, IA

Built 1972 Load: 30.0 t ADT: 890

FM

Poor

Over: E CEDAR CREEK

087312103, Calhoun, IA

Built 1970 Load: 30.0 t ADT: 180

FM

Poor

Over: W BR LITTLE SIOUX

100381301, Dickinson, IA

Built 1977 Load: 30.0 t ADT: 61

FM

Poor

Over: ASHTON CREEK

089411202, Ida, IA

Built 1974 Load: 30.0 t ADT: 290

HIGHWAY F-70 W

Poor

Over: WALNUT CREEK

078213401, Jasper, IA

Built 1971 Load: 30.0 t ADT: 540

FM

Poor

Over: WAPSI CREEK

078040110, Muscatine, IA

Built 1971 Load: 30.0 t ADT: 3,080

296TH ST

Poor

Over: CREEK

080E11305, Scott, IA

Built 1974 Load: 30.0 t ADT: 200

FM

Poor

Over: EAST PLATTE RIVER

071301701, Union, IA

Built 1963 Load: 30.0 t ADT: 199

FM

Poor

Over: DD NO 69

088301201, Webster, IA

Built 1974 Load: 30.0 t ADT: 339

FM

Poor

Over: SOLDIER CR (DD NO 247)

089280905, Webster, IA

Built 1974 Load: 30.0 t ADT: 2,364

C54 265TH ST

Poor

Over: DRAINAGE

091242505, Wright, IA

Built 1976 Load: 30.0 t ADT: 569

FM

Poor

Over: INDIAN CREEK

094471301, Sioux, IA

Built 1965 Load: 30.1 t ADT: 469

B46

Poor

Over: NO NAME CREEK

095472101, Sioux, IA

Built 1966 Load: 30.1 t ADT: 538

FM

Poor

Over: BIG CREEK

088433306, Woodbury, IA

Built 1964 Load: 30.1 t ADT: 270

290TH ST

Poor

Over: CREEK

078340305, Audubon, IA

Built 1940 Load: 30.2 t ADT: 15

212TH ST

Poor

Over: DRY RUN CREEK

093140202, Bremer, IA

Built 1977 Load: 30.2 t ADT: 226

FM

Poor

Over: LAKE CR.

087321901, Calhoun, IA

Built 1978 Load: 30.2 t ADT: 359

LOCAL

Poor

Over: CAMP CK

087342101, Calhoun, IA

Built 1973 Load: 30.2 t ADT: 279

W AVE

Poor

Over: CREEK

082293504, Greene, IA

Built 1900 Load: 30.2 t ADT: 21

FM

Poor

Over: MOSQUITO CREEK

081310202, Guthrie, IA

Built 1978 Load: 30.2 t ADT: 159

LOC 210TH AVE

Poor

Over: BUFFALO CREEK

097270402, Kossuth, IA

Built 1971 Load: 30.2 t ADT: 143

FM

Poor

Over: SUGAR CREEK

066061403, Lee, IA

Built 1976 Load: 30.2 t ADT: 650

LOCAL

Poor

Over: WATERWAY

077270303, Madison, IA

Built 1950 Load: 30.2 t ADT: 40

FM

Poor

Over: MUD CREEK

078E10604, Muscatine, IA

Built 1972 Load: 30.2 t ADT: 1,600

FM

Poor

Over: OVERFLOW FROM SUGAR CRK

078020924, Muscatine, IA

Built 1971 Load: 30.2 t ADT: 1,640

LOCAL

Poor

Over: KIBBE CREEK

084141002, Tama, IA

Built 1991 Load: 30.2 t ADT: 49

S 40

Poor

Over: DRAINAGE

068211502, Wayne, IA

Built 1972 Load: 30.2 t ADT: 680

FM

Poor

Over: SOUTH LIZARD CREEK

089292605, Webster, IA

Built 1975 Load: 30.2 t ADT: 230

ZANETA RD

Poor

Over: BLACK HAWK CREEK

88-14-33-03, Black Hawk, IA

Built 1942 Load: 30.3 t ADT: 982

FM

Poor

Over: TRIB. OF BEAVER CREEK

082280305, Boone, IA

Built 1948 Load: 30.3 t ADT: 279

432ND AVENUE

Poor

Over: ELK RIVER

083E61506, Clinton, IA

Built 1968 Load: 30.3 t ADT: 310

LOCAL

Poor

Over: DRAINAGE

074260501, Madison, IA

Built 1981 Load: 30.3 t ADT: 45

390TH

Poor

Over: SHELLROCK RIVER

098201201, Worth, IA

Built 1958 Load: 30.3 t ADT: 363

FM

Poor

Over: LITTLE WALNUT CREEK

069180902, Appanoose, IA

Built 1967 Load: 30.4 t ADT: 530

FM

Poor

Over: CEDAR CREEK

087311704, Calhoun, IA

Built 1972 Load: 30.4 t ADT: 60

FM

Poor

Over: LITTLE CEDAR

095140904, Chickasaw, IA

Built 1965 Load: 30.4 t ADT: 196

FM

Poor

Over: DUGOUT CREEK

099381002, Dickinson, IA

Built 1970 Load: 30.4 t ADT: 843

FM

Poor

Over: BEAVER CREEK

095182202, Floyd, IA

Built 1965 Load: 30.4 t ADT: 206

FM

Poor

Over: SOUTH RACCOON RIVER

078301203, Guthrie, IA

Built 1975 Load: 30.4 t ADT: 329

FM 1870 330TH

Poor

Over: WINNEBAGO RIVER

097241203, Hancock, IA

Built 1963 Load: 30.4 t ADT: 2,192

LOCAL

Poor

Over: SOUTH FORK IOWA RIVER

088212906, Hardin, IA

Built 1939 Load: 30.4 t ADT: 39

FM

Poor

Over: SOUTH FORK IOWA RIVER

088213403, Hardin, IA

Built 1964 Load: 30.4 t ADT: 373

HIGHWAY S-74 S

Poor

Over: CARSON CREEK

078190303, Jasper, IA

Built 1964 Load: 30.4 t ADT: 810

FM

Poor

Over: BR OF ENGLISH CREEK

073211102, Lucas, IA

Built 1963 Load: 30.4 t ADT: 880

FM

Poor

Over: RAT CREEK

098432202, Lyon, IA

Built 1966 Load: 30.4 t ADT: 199

FM

Poor

Over: LITTLE OTTER CREEK

098433402, Lyon, IA

Built 1968 Load: 30.4 t ADT: 199

FM

Poor

Over: KLONDIKE CREEK

099481502, Lyon, IA

Built 1966 Load: 30.4 t ADT: 309

FM

Poor

Over: MUD CREEK

100471301, Lyon, IA

Built 1970 Load: 30.4 t ADT: 290

FM

Poor

Over: JIM CREEK

077290306, Madison, IA

Built 1972 Load: 30.4 t ADT: 597

Showing 18,901-18,950 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.