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

FM

Poor

Over: FAMERS GARRETSON DITCH

085450404, Monona, IA

Built 1962 Load: 16.8 t ADT: 578

LOCAL

Poor

Over: CREEK

098390504, Osceola, IA

Built 1936 Load: 16.8 t ADT: 62

LOCAL

Poor

Over: DRAINAGE

090461903, Plymouth, IA

Built 1955 Load: 16.8 t ADT: 30

IMPALA AVE

Poor

Over: MINK CREEK

092460502, Plymouth, IA

Built 1938 Load: 16.8 t ADT: 26

FIR AVE

Poor

Over: BULL RUN

092473302, Plymouth, IA

Built 1948 Load: 16.8 t ADT: 30

180TH ST

Poor

Over: WESTFIELD CREEK

092481501, Plymouth, IA

Built 1948 Load: 16.8 t ADT: 20

LOCAL

Poor

Over: NO NAME CREEK

086373502, Sac, IA

Built 1964 Load: 16.8 t ADT: 45

LOCAL

Poor

Over: STREAM

068220102, Wayne, IA

Built 1967 Load: 16.8 t ADT: 60

FM

Poor

Over: LIZARD CREEK

089300104, Webster, IA

Built 1965 Load: 16.8 t ADT: 549

FM

Poor

Over: LIZARD CREEK

089301206, Webster, IA

Built 1965 Load: 16.8 t ADT: 549

LOCAL

Poor

Over: RUTT BRANCH

075320402, Adair, IA

Built 1900 Load: 16.9 t ADT: 35

ADAMS-MONTGOM.

Poor

Over: SIN CREEK

073351904, Adams, IA

Built 1979 Load: 17.0 t ADT: 5

LOCAL RD

Poor

Over: BR SUTTLE CREEK

096043004, Allamakee, IA

Built 1900 Load: 17.0 t ADT: 70

FM

Poor

Over: BRANCH YELLOW RIVER

096061608, Allamakee, IA

Built 1922 Load: 17.0 t ADT: 373

FM

Poor

Over: BEAR CREEK

083101306, Benton, IA

Built 1957 Load: 17.0 t ADT: 1,414

10TH AVE

Poor

Over: MINNOW CREEK

082122301, Benton, IA

Built 1900 Load: 17.0 t ADT: 349

BIG WOODS RD

Poor

Over: TRIB TO CEDAR RIVER

90-13-18-02-10, Black Hawk, IA

Built 1953 Load: 17.0 t ADT: 59

LOCAL

Poor

Over: DRAINAGE DITCH

091372402, Buena Vista, IA

Built 1971 Load: 17.0 t ADT: 100

FM

Poor

Over: CEDAR CREEK

086323501, Calhoun, IA

Built 1938 Load: 17.0 t ADT: 34

FM - LANSING

Poor

Over: WATERWAY

076363401, Cass, IA

Built 1900 Load: 17.0 t ADT: 379

FM-L AVE.

Poor

Over: SMALL CREEK

092412402, Cherokee, IA

Built 1900 Load: 17.0 t ADT: 429

220 ST

Poor

Over: BR ROBINSON CREEK

088060401, Delaware, IA

Built 1922 Load: 17.0 t ADT: 1,061

FM 170 ST

Poor

Over: SMALL STREAM

089040807, Delaware, IA

Built 1955 Load: 17.0 t ADT: 79

LOCAL

Poor

Over: EAST FORK CROOKED CREEK

072040503, Des Moines, IA

Built 1950 Load: 17.0 t ADT: 26

110TH STREET

Poor

Over: SMALL STREAM

091222001, Franklin, IA

Built 1936 Load: 17.0 t ADT: 20

LOCAL

Poor

Over: BRANCH WOLF CREEK

086181303, Grundy, IA

Built 1914 Load: 17.0 t ADT: 5

FM

Poor

Over: CREEK

086202407, Hardin, IA

Built 1900 Load: 17.0 t ADT: 373

FM

Poor

Over: CREEK

087222104, Hardin, IA

Built 1942 Load: 17.0 t ADT: 255

X030 EXT(GEODE)

Poor

Over: CEDAR CREEK

070052506, Henry, IA

Built 1935 Load: 17.0 t ADT: 70

FM OAK AVE

Poor

Over: UPPER IOWA

100120904, Howard, IA

Built 1950 Load: 17.0 t ADT: 393

LOCAL

Poor

Over: EAST FORK BATTLE CREEK

088402901, Ida, IA

Built 1900 Load: 17.0 t ADT: 35

FM

Poor

Over: SMALL

089391302, Ida, IA

Built 1900 Load: 17.0 t ADT: 379

LOCAL

Poor

Over: FULLINGTON CREEK

080202104, Jasper, IA

Built 1959 Load: 17.0 t ADT: 35

LOCAL

Poor

Over: BR.WALNUT CREEK

073082002, Jefferson, IA

Built 1926 Load: 17.0 t ADT: 5

VAN BUREN ST

Poor

Over: RALSTON CREEK

079061500, Johnson, IA

Built 1935 Load: 17.0 t ADT: 1,082

FM

Poor

Over: CLANTON CREEK

074281605, Madison, IA

Built 1932 Load: 17.0 t ADT: 477

LOCAL RD

Poor

Over: DRAINAGE

076283301, Madison, IA

Built 1930 Load: 17.0 t ADT: 219

LOCAL RD

Poor

Over: DRAINAGE

077290502, Madison, IA

Built 1940 Load: 17.0 t ADT: 60

LOCAL

Poor

Over: SOUTH TIMBER CREEK

082170603, Marshall, IA

Built 1932 Load: 17.0 t ADT: 11

720TH AVE

Poor

Over: STREAM

073163404, Monroe, IA

Built 1965 Load: 17.0 t ADT: 45

150TH STREET

Poor

Over: EAST NISHNABOTNA RIVER

070392705, Page, IA

Built 1937 Load: 17.0 t ADT: 139

LOCAL

Poor

Over: STREAM

089361104, Sac, IA

Built 1953 Load: 17.0 t ADT: 26

LOCAL

Poor

Over: BOYER RIVER

089373501, Sac, IA

Built 1916 Load: 17.0 t ADT: 60

CORRECTIONVILLE

Poor

Over: BACON CREEK

000000000, Woodbury, IA

Built 1900 Load: 17.0 t ADT: 1,664

FM

Poor

Over: STREAM

068160704, Appanoose, IA

Built 1958 Load: 17.1 t ADT: 30

FM

Poor

Over: STREAM

069173604, Appanoose, IA

Built 1958 Load: 17.1 t ADT: 100

LOCAL

Poor

Over: E NISHNABOTNA RIVER

081343001, Audubon, IA

Built 1971 Load: 17.1 t ADT: 26

LOCAL

Poor

Over: BR RACCOON RIVER

091361102, Buena Vista, IA

Built 1917 Load: 17.1 t ADT: 40

LOCAL

Poor

Over: BR RACCOON RIVER

092361702, Buena Vista, IA

Built 1920 Load: 17.1 t ADT: 20

LOCAL - UPLAND

Poor

Over: WATERWAY

074371603, Cass, IA

Built 1983 Load: 17.1 t ADT: 26

Showing 17,551-17,600 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.