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

IA 146

Fair

Over: NORTH SKUNK RIVER

2.7 MILES N OF JCT US 63, Poweshiek, IA

Built 1958 Load: 26.3 t ADT: 1,290

FM

Fair

Over: LIME CREEK

086363301, Sac, IA

Built 1922 Load: 26.3 t ADT: 50

FM

Fair

Over: BOYER RIVER

088372101, Sac, IA

Built 1967 Load: 26.3 t ADT: 20

D 36 (255TH ST)

Fair

Over: DRAINAGE DITCH

088372403, Sac, IA

Built 1933 Load: 26.3 t ADT: 679

LOCAL

Fair

Over: CAMP CREEK

078373501, Shelby, IA

Built 1945 Load: 26.3 t ADT: 15

EB US 30

Fair

Over: BIKE PATH & TRAIL

1.1 MILES W OF JCT US 69, Story, IA

Built 1971 Load: 26.3 t ADT: 11,500

590TH AVE

Fair

Over: LONG DICK CREEK

085230302, Story, IA

Built 1975 Load: 26.3 t ADT: 60

GARNET DR

Fair

Over: FLOOD CHANNEL

A09250755, Story, IA

Built 1975 Load: 26.3 t ADT: 555

FM

Fair

Over: CREEK

087422401, Woodbury, IA

Built 1970 Load: 26.3 t ADT: 210

FM

Fair

Over: BACON CREEK

0884206, Woodbury, IA

Built 1967 Load: 26.3 t ADT: 180

LOCAL

Fair

Over: BOONE RIVER

092260703, Wright, IA

Built 1968 Load: 26.3 t ADT: 63

UNION AVENUE

Fair

Over: STREAM

071323402, Adams, IA

Built 1966 Load: 26.4 t ADT: 26

195TH STREEG

Fair

Over: BROWN BRANCH

072332103, Adams, IA

Built 1969 Load: 26.4 t ADT: 15

HICKORY AVENUE

Fair

Over: STREAM

073343204, Adams, IA

Built 1967 Load: 26.4 t ADT: 40

ELM AVENUE

Fair

Over: SHOW CREEK

073353602, Adams, IA

Built 1966 Load: 26.4 t ADT: 29

LOCAL

Fair

Over: PLEASANT RUN

078353602, Audubon, IA

Built 1973 Load: 26.4 t ADT: 11

FM

Fair

Over: BIG CREEK

082250903, Boone, IA

Built 1940 Load: 26.4 t ADT: 50

250TH ST

Fair

Over: QUARTER SECTION RUN

091132405, Bremer, IA

Built 1995 Load: 26.4 t ADT: 97

180TH ST

Fair

Over: BASKIN CR

092131801, Bremer, IA

Built 2000 Load: 26.4 t ADT: 39

200TH ST

Fair

Over: BASKINS CREEK

092133001, Bremer, IA

Built 2003 Load: 26.4 t ADT: 33

110TH ST

Fair

Over: HORTON CREEK

093141201, Bremer, IA

Built 1995 Load: 26.4 t ADT: 29

FAIRVIEW AVE

Fair

Over: HORTON CREEK

093141202, Bremer, IA

Built 2002 Load: 26.4 t ADT: 29

120TH ST

Fair

Over: HORTON CREEK

093141401, Bremer, IA

Built 2004 Load: 26.4 t ADT: 49

247TH ST

Fair

Over: ROCK RUN CREEK

080031609, Cedar, IA

Built 1974 Load: 26.4 t ADT: 15

LOCAL

Fair

Over: BUCK CREEK

082391506, Crawford, IA

Built 1961 Load: 26.4 t ADT: 41

LOCAL

Fair

Over: COON CREEK

083392703, Crawford, IA

Built 1978 Load: 26.4 t ADT: 72

LOCAL

Fair

Over: OTTER CREEK

085391305, Crawford, IA

Built 1977 Load: 26.4 t ADT: 62

110 STREET

Fair

Over: HUNTER BRANCH

070401003, Fremont, IA

Built 1936 Load: 26.4 t ADT: 26

LOCAL

Fair

Over: SMALL STREAM

080171006, Jasper, IA

Built 1925 Load: 26.4 t ADT: 51

LOCAL

Fair

Over: DRAINAGE

076273505, Madison, IA

Built 1996 Load: 26.4 t ADT: 29

FM

Fair

Over: SMALL STREAM

076151605, Mahaska, IA

Built 1979 Load: 26.4 t ADT: 300

IA 316

Fair

Over: DES MOINES RIVER

3.9 MILES N OF JCT IA 5, Polk, IA

Built 1968 Load: 26.4 t ADT: 810

FM

Fair

Over: STREAM

079222408, Polk, IA

Built 1979 Load: 26.4 t ADT: 856

FM

Fair

Over: BR SKUNK RIVER

080220906, Polk, IA

Built 1927 Load: 26.4 t ADT: 89

SB I-29

Fair

Over: OVER BNSF RR

1.3 MI. S OF JCT. 92, Pottawattamie, IA

Built 1968 Load: 26.4 t ADT: 12,100

LOCAL

Fair

Over: DEEP RIVER

078130206, Poweshiek, IA

Built 1961 Load: 26.4 t ADT: 20

LOCAL

Fair

Over: STREAM

078160202, Poweshiek, IA

Built 2002 Load: 26.4 t ADT: 15

LOCAL

Fair

Over: SALT CREEK

084140201, Tama, IA

Built 2005 Load: 26.4 t ADT: 20

LOCAL

Fair

Over: WOLF CREEK

085151604, Tama, IA

Built 1985 Load: 26.4 t ADT: 33

250TH ST

Fair

Over: WOLF CREEK

0874420, Woodbury, IA

Built 2000 Load: 26.4 t ADT: 11

FM

Fair

Over: NISHNABOTNA RIVER (EF)

080361503, Audubon, IA

Built 1963 Load: 26.5 t ADT: 110

LOCAL

Fair

Over: LITTLE BEAR CREEK

083101301, Benton, IA

Built 1984 Load: 26.5 t ADT: 44

LOCAL

Fair

Over: BRANCH PRAIRIE CREEK

083112602, Benton, IA

Built 1984 Load: 26.5 t ADT: 26

LOCAL

Fair

Over: MUD CREEK

084112304, Benton, IA

Built 1985 Load: 26.5 t ADT: 26

LOCAL

Fair

Over: BR RACCOON RIVER

091361504, Buena Vista, IA

Built 1970 Load: 26.5 t ADT: 26

LOCAL

Fair

Over: MAPLE CREEK

092382901, Buena Vista, IA

Built 1965 Load: 26.5 t ADT: 11

LOCAL RD

Fair

Over: STORM CREEK

084340501, Carroll, IA

Built 1980 Load: 26.5 t ADT: 131

LOCAL

Fair

Over: SMALL STREAM

070143504, Davis, IA

Built 1985 Load: 26.5 t ADT: 11

FM

Fair

Over: SMALL STREAM

070032104, Des Moines, IA

Built 1968 Load: 26.5 t ADT: 2,000

LOCAL

Fair

Over: EAST FORK CROOKED CREEK

072040601, Des Moines, IA

Built 1965 Load: 26.5 t ADT: 16

Showing 4,551-4,600 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.