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

510TH STREET

Poor

Over: STREAM

077380304, Pottawattamie, IA

Built 1992 Load: 22.3 t ADT: 5

FM

Poor

Over: COTTON CREEK

074223202, Warren, IA

Built 1974 Load: 22.3 t ADT: 50

LOCAL

Poor

Over: STREAM

068182801, Appanoose, IA

Built 1948 Load: 22.4 t ADT: 30

LOCAL 260TH ST

Poor

Over: LIME CR

088102601, Buchanan, IA

Built 1986 Load: 22.4 t ADT: 41

LOCAL

Poor

Over: HONEY CREEK

087222202, Hardin, IA

Built 1980 Load: 22.4 t ADT: 21

LOCAL RD

Poor

Over: SMALL

075291205, Madison, IA

Built 1976 Load: 22.4 t ADT: 60

LOCAL

Poor

Over: DD 41

095332402, Palo Alto, IA

Built 1948 Load: 22.4 t ADT: 46

FM

Poor

Over: SILVER CREEK

078401103, Shelby, IA

Built 1960 Load: 22.4 t ADT: 131

E15/115TH ST

Poor

Over: LONG DICK CREEK

085230903, Story, IA

Built 1964 Load: 22.4 t ADT: 1,028

LOCAL

Poor

Over: CREEK

070090902, Van Buren, IA

Built 1977 Load: 22.4 t ADT: 26

FM

Poor

Over: BR CEDAR RIVER

086102804, Benton, IA

Built 1975 Load: 22.5 t ADT: 150

180TH

Poor

Over: EAST CREEK

095202601, Cerro Gordo, IA

Built 1937 Load: 22.5 t ADT: 16

470TH STREET

Poor

Over: JORDAN CREEK

075392402, Pottawattamie, IA

Built 1967 Load: 22.5 t ADT: 26

FM

Poor

Over: STREAM

079153201, Poweshiek, IA

Built 1948 Load: 22.5 t ADT: 30

FM

Poor

Over: SUGAR CREEK

079163003, Poweshiek, IA

Built 1982 Load: 22.5 t ADT: 15

LOCAL

Poor

Over: RICHLAND CREEK

082151903, Tama, IA

Built 1991 Load: 22.5 t ADT: 11

MALLARD

Poor

Over: DRAINAGE DITCH

098200702, Worth, IA

Built 1900 Load: 22.5 t ADT: 15

LOCAL

Poor

Over: BIG CREEK

083261301, Boone, IA

Built 1915 Load: 22.6 t ADT: 26

280 STREET

Poor

Over: MILL CREEK

067400801, Fremont, IA

Built 1961 Load: 22.6 t ADT: 51

FM

Poor

Over: BLACKHAWK CREEK

087161304, Grundy, IA

Built 1967 Load: 22.6 t ADT: 579

WASHINGTON STREET

Poor

Over: ODEBOLT CREEK

087401408, Ida, IA

Built 1972 Load: 22.6 t ADT: 1,635

FM

Poor

Over: LITTLE ROCK RIVER

100433503, Lyon, IA

Built 1968 Load: 22.6 t ADT: 131

LOCAL

Poor

Over: STREAM

077192805, Marion, IA

Built 1960 Load: 22.6 t ADT: 30

LOCAL

Poor

Over: PILOT CK

093322002, Pocahontas, IA

Built 1972 Load: 22.6 t ADT: 15

130TH AVE

Poor

Over: CREEK

080E33206, Scott, IA

Built 1972 Load: 22.6 t ADT: 122

CHIMNEY ROCK RD

Poor

Over: CREEK

099091704, Winneshiek, IA

Built 1900 Load: 22.6 t ADT: 26

FM

Poor

Over: IOWA RIVER

091230308, Wright, IA

Built 1968 Load: 22.6 t ADT: 199

FM

Poor

Over: EAGLE CREEK

091252904, Wright, IA

Built 1963 Load: 22.6 t ADT: 818

LOCAL

Poor

Over: VILLAGE CREEK

098052701, Allamakee, IA

Built 1966 Load: 22.7 t ADT: 157

FM

Poor

Over: WAPSIPINICON RIVER

089100802, Buchanan, IA

Built 1962 Load: 22.7 t ADT: 1,390

LOCAL

Poor

Over: STREAM

091381701, Buena Vista, IA

Built 1915 Load: 22.7 t ADT: 15

LOCAL

Poor

Over: SMALL

082331401, Carroll, IA

Built 1979 Load: 22.7 t ADT: 11

LOCAL (DEAD END

Poor

Over: FIELD STREAM

084330304, Carroll, IA

Built 1900 Load: 22.7 t ADT: 11

LOCAL

Poor

Over: CREEK

076363604, Cass, IA

Built 1997 Load: 22.7 t ADT: 21

M21 W AVE

Poor

Over: BRANCH MAPLE RIVER

091390202, Cherokee, IA

Built 1970 Load: 22.7 t ADT: 369

LOCAL

Poor

Over: SPRING BRANCH CREEK

094132202, Chickasaw, IA

Built 1981 Load: 22.7 t ADT: 15

LOCAL

Poor

Over: CREEK

095131002, Chickasaw, IA

Built 1969 Load: 22.7 t ADT: 82

FM

Poor

Over: COLD SPRING ,BRANCH

071022206, Des Moines, IA

Built 1959 Load: 22.7 t ADT: 40

FM TULIP AVE

Poor

Over: WEST FORK CEDAR CREEK

093192804, Franklin, IA

Built 1966 Load: 22.7 t ADT: 137

FM

Poor

Over: SMALL CREEK

080322303, Guthrie, IA

Built 1965 Load: 22.7 t ADT: 417

FM

Poor

Over: KEIGLEY CREEK

086252402, Hamilton, IA

Built 1949 Load: 22.7 t ADT: 26

FM

Poor

Over: CREEK

086192801, Hardin, IA

Built 1960 Load: 22.7 t ADT: 462

LOCAL

Poor

Over: BERRY BRANCH

071072905, Henry, IA

Built 1974 Load: 22.7 t ADT: 30

FM

Poor

Over: LYNN CREEK

072071201, Henry, IA

Built 1964 Load: 22.7 t ADT: 340

KINGS RD

Poor

Over: TURKEY RIVER

098110209, Howard, IA

Built 1961 Load: 22.7 t ADT: 25

LOCAL 125TH ST

Poor

Over: LITTLE WAPSIPINICON RVR

098140303, Howard, IA

Built 1984 Load: 22.7 t ADT: 26

SW ANGLE RD

Poor

Over: BR OLD MAN'S CR

078081203, Johnson, IA

Built 1920 Load: 22.7 t ADT: 92

FM

Poor

Over: STREAM

074111003, Keokuk, IA

Built 1951 Load: 22.7 t ADT: 80

FM

Poor

Over: N SKUNK RIVER

077152210, Mahaska, IA

Built 1951 Load: 22.7 t ADT: 140

FM

Poor

Over: LUTES CREEK

082170701, Marshall, IA

Built 1957 Load: 22.7 t ADT: 697

Showing 18,301-18,350 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.