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

Fair

Over: SUGAR CREEK

066053105, Lee, IA

Built 1952 Load: 17.1 t ADT: 80

FM

Fair

Over: SUGAR CREEK

068053204, Lee, IA

Built 1951 Load: 17.1 t ADT: 70

LINN-BENTON RD

Fair

Over: BEAR CR

084081804, Linn, IA

Built 1948 Load: 17.1 t ADT: 196

LOCAL

Fair

Over: CHARITON RIVER

071221702, Lucas, IA

Built 1951 Load: 17.1 t ADT: 82

FM

Fair

Over: MIDDLE CREEK

076152304, Mahaska, IA

Built 1950 Load: 17.1 t ADT: 20

FM

Fair

Over: MOON CREEK

077140605, Mahaska, IA

Built 1951 Load: 17.1 t ADT: 25

FM

Fair

Over: WILLOW CREEK

082422703, Monona, IA

Built 1960 Load: 17.1 t ADT: 11

FM

Fair

Over: HAITZ DD

084450101, Monona, IA

Built 1961 Load: 17.1 t ADT: 34

LOCAL

Fair

Over: TRIB MAPLE RIVER

085421002, Monona, IA

Built 1900 Load: 17.1 t ADT: 20

LOCAL

Fair

Over: MILLER CREEK

073173603, Monroe, IA

Built 1947 Load: 17.1 t ADT: 20

LOCAL RD

Fair

Over: WHITES CREEK

073181905, Monroe, IA

Built 1968 Load: 17.1 t ADT: 80

LOCAL

Fair

Over: CEDAR CREEK

073192001, Monroe, IA

Built 1997 Load: 17.1 t ADT: 30

FM

Fair

Over: WEST NODAWAY

073362803, Montgomery, IA

Built 1957 Load: 17.1 t ADT: 29

FM

Fair

Over: OTTER CREEK

098422701, Osceola, IA

Built 1951 Load: 17.1 t ADT: 60

V AVENUE

Fair

Over: STREAM

067362204, Page, IA

Built 1959 Load: 17.1 t ADT: 40

260TH STREET

Fair

Over: BUCHANAN CREEK

068363601, Page, IA

Built 1959 Load: 17.1 t ADT: 60

L AVENUE

Fair

Over: EAST TARKIO RIVER

069371802, Page, IA

Built 1958 Load: 17.1 t ADT: 34

FM

Fair

Over: DD 48

094322502, Palo Alto, IA

Built 1965 Load: 17.1 t ADT: 40

IA 12

Fair

Over: DRAINAGE DITCH

1.5 mi S of S jct SR K18, Plymouth, IA

Built 1957 Load: 17.1 t ADT: 1,840

LOCAL

Fair

Over: LIZARD CREEK

092330901, Pocahontas, IA

Built 1963 Load: 17.1 t ADT: 26

LOCAL

Fair

Over: LITTLE CEDAR CK

092342902, Pocahontas, IA

Built 1964 Load: 17.1 t ADT: 11

350TH ST

Fair

Over: DRAINAGE

074411202, Pottawattamie, IA

Built 2000 Load: 17.1 t ADT: 45

290TH STREET

Fair

Over: MOSQUITO CREEK

077422512, Pottawattamie, IA

Built 1966 Load: 17.1 t ADT: 45

110TH ST

Fair

Over: KEIGLEY BRANCH

085240801, Story, IA

Built 1978 Load: 17.1 t ADT: 170

FM

Fair

Over: SMALL STREAM

084132301, Tama, IA

Built 1959 Load: 17.1 t ADT: 314

LOCAL

Fair

Over: NODAWAY RIVER DITCH

070350705, Taylor, IA

Built 1966 Load: 17.1 t ADT: 34

LOCAL

Fair

Over: SMALL STREAM

072283605, Union, IA

Built 2002 Load: 17.1 t ADT: 26

LOCAL

Fair

Over: CREEK

068091708, Van Buren, IA

Built 1968 Load: 17.1 t ADT: 11

FM

Fair

Over: BADGER CREEK

077251902, Warren, IA

Built 1950 Load: 17.1 t ADT: 390

FM

Fair

Over: SMITH CREEK

077092702, Washington, IA

Built 1952 Load: 17.1 t ADT: 70

LOCAL ROAD

Fair

Over: CREEK

099102301, Winneshiek, IA

Built 1966 Load: 17.1 t ADT: 39

IRONWOOD AVENUE

Fair

Over: STREAM

071342202, Adams, IA

Built 1979 Load: 17.2 t ADT: 15

FM-UNION AVE

Fair

Over: STREAM

072321502, Adams, IA

Built 1954 Load: 17.2 t ADT: 50

WILLOW AVENUE

Fair

Over: STREAM

072322402, Adams, IA

Built 1968 Load: 17.2 t ADT: 5

210TH STREET

Fair

Over: METZ CREEK

072323401, Adams, IA

Built 1965 Load: 17.2 t ADT: 11

LOCAL

Fair

Over: LAKE CREEK

087333402, Calhoun, IA

Built 1955 Load: 17.2 t ADT: 26

LOCAL

Fair

Over: DD 12

089313601, Calhoun, IA

Built 1973 Load: 17.2 t ADT: 34

LOCAL

Fair

Over: FIELD STREAM

084340403, Carroll, IA

Built 1968 Load: 17.2 t ADT: 120

130TH

Fair

Over: CREEK

094222401, Cerro Gordo, IA

Built 1913 Load: 17.2 t ADT: 62

FM

Fair

Over: BRANCH LONG CREEK

071273405, Clarke, IA

Built 1966 Load: 17.2 t ADT: 11

LOCAL

Fair

Over: NISHNABOTNA RIVER

082383402, Crawford, IA

Built 1953 Load: 17.2 t ADT: 46

LOCAL

Fair

Over: N CHEQUEST LAKE CREEK

070132604, Davis, IA

Built 1957 Load: 17.2 t ADT: 60

LOCAL

Fair

Over: N CHEQUEST LAKE CREEK

070132704, Davis, IA

Built 1955 Load: 17.2 t ADT: 60

FM

Fair

Over: STREAM

069263002, Decatur, IA

Built 1998 Load: 17.2 t ADT: 40

290TH AVE

Fair

Over: WELDON CREEK

070241702, Decatur, IA

Built 2012 Load: 17.2 t ADT: 29

LOCAL

Fair

Over: CEDAR FORK

072032103, Des Moines, IA

Built 1965 Load: 17.2 t ADT: 73

289TH ST

Fair

Over: DRY RUN

086E30109, Jackson, IA

Built 1930 Load: 17.2 t ADT: 5

170TH ST.

Fair

Over: BRANCH KITTY CREEK

085031401, Jones, IA

Built 1978 Load: 17.2 t ADT: 88

222ND AVE.

Fair

Over: GROVE CREEK

086040304, Jones, IA

Built 1976 Load: 17.2 t ADT: 44

FM

Fair

Over: SUGAR CREEK

066062303, Lee, IA

Built 1957 Load: 17.2 t ADT: 80

Showing 1,851-1,900 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.