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

081022001, Cedar, IA

Built 1975 Load: 33.0 t ADT: 45

FM 280TH AVE

Fair

Over: PICKEREL RUN

096351704, Clay, IA

Built 1990 Load: 33.0 t ADT: 120

FM 280TH ST

Fair

Over: BIG MEADOW CREEK

097350701, Clay, IA

Built 1977 Load: 33.0 t ADT: 50

FM 320TH ST

Fair

Over: DRAINAGE DIST #37 DITCH

097353301, Clay, IA

Built 1978 Load: 33.0 t ADT: 34

FM 280TH ST

Fair

Over: LITTLE SIOUX RIVER

097370701, Clay, IA

Built 1966 Load: 33.0 t ADT: 270

DOMINO RD

Fair

Over: SCHNEIDERS CREEK

093052809, Clayton, IA

Built 1973 Load: 33.0 t ADT: 619

FM

Fair

Over: LITTLE RIVER

068250603, Decatur, IA

Built 2000 Load: 33.0 t ADT: 26

LOCAL

Fair

Over: MUDDY CREEK

098351601, Dickinson, IA

Built 1979 Load: 33.0 t ADT: 41

FM

Fair

Over: STONY CREEK

098380701, Dickinson, IA

Built 1977 Load: 33.0 t ADT: 934

FM

Fair

Over: SMALL

087E13006, Dubuque, IA

Built 1978 Load: 33.0 t ADT: 720

FM

Fair

Over: JOHN'S CREEK

088023604, Dubuque, IA

Built 1972 Load: 33.0 t ADT: 680

LOCAL

Fair

Over: BLACK CAT CREEK

0983115, Emmet, IA

Built 1987 Load: 33.0 t ADT: 60

FM

Fair

Over: JACK CREEK

0983222, Emmet, IA

Built 1973 Load: 33.0 t ADT: 240

FM

Fair

Over: JACK CREEK

0993222, Emmet, IA

Built 1973 Load: 33.0 t ADT: 529

FM

Fair

Over: JACK CREEK DD #17

0993234, Emmet, IA

Built 1977 Load: 33.0 t ADT: 529

FM

Fair

Over: BROWN CREEK (DD#121)

099330502, Emmet, IA

Built 1971 Load: 33.0 t ADT: 379

FM

Fair

Over: D.D.#40

100322702, Emmet, IA

Built 1984 Load: 33.0 t ADT: 578

FM

Fair

Over: SOLDIER CREEK

0100322702, Emmet, IA

Built 1984 Load: 33.0 t ADT: 578

FM

Fair

Over: DRY RUN CREEK

094152103, Floyd, IA

Built 1979 Load: 33.0 t ADT: 530

FM

Fair

Over: DRAINAGE

094183406, Floyd, IA

Built 1988 Load: 33.0 t ADT: 39

FM

Fair

Over: WHISKEY CREEK

096183401, Floyd, IA

Built 1988 Load: 33.0 t ADT: 79

FM (70TH ST)

Fair

Over: DD NO. 6

090211101, Franklin, IA

Built 1956 Load: 33.0 t ADT: 570

FM 110TH ST

Fair

Over: MAYNES CREEK

091212101, Franklin, IA

Built 1976 Load: 33.0 t ADT: 88

FM 100TH ST

Fair

Over: SMALL STREAM

091222901, Franklin, IA

Built 1961 Load: 33.0 t ADT: 560

LOCAL

Fair

Over: STREAM

089151401, Grundy, IA

Built 1977 Load: 33.0 t ADT: 97

LOCAL

Fair

Over: KEIGLEY CR

086243101, Hamilton, IA

Built 1977 Load: 33.0 t ADT: 15

LOCAL

Fair

Over: CROOKED CREEK

086251802, Hamilton, IA

Built 1970 Load: 33.0 t ADT: 15

LOCAL

Fair

Over: DRAINAGE DITCH

089231503, Hamilton, IA

Built 1970 Load: 33.0 t ADT: 26

LOCAL

Fair

Over: DRAINAGE DITCH

089231503, Hamilton, IA

Built 1970 Load: 33.0 t ADT: 26

FM 1220 260 ST

Fair

Over: DRAINAGE DITCH 1&2

096251301, Hancock, IA

Built 1973 Load: 33.0 t ADT: 26

FM

Fair

Over: CREEK

087220502, Hardin, IA

Built 1970 Load: 33.0 t ADT: 177

FM SE 670TH ST

Fair

Over: PRAIRIE CREEK

077053009, Johnson, IA

Built 1966 Load: 33.0 t ADT: 100

580TH ST SE

Fair

Over: OTTER CREEK

077060101, Johnson, IA

Built 1964 Load: 33.0 t ADT: 81

FM

Fair

Over: STREAM

078071604, Johnson, IA

Built 1900 Load: 33.0 t ADT: 460

FM SW KANAS AVE

Fair

Over: PICAYUNE CREEK

078072602, Johnson, IA

Built 1978 Load: 33.0 t ADT: 90

NORTH MAIN ST

Fair

Over: MAQUOKETA RIVER

086032209, Jones, IA

Built 1969 Load: 33.0 t ADT: 2,787

IA 38

Fair

Over: WAPSIPINICON OVERFLOW

0.1 MI. S OF JCT. SR E45, Jones, IA

Built 1977 Load: 33.0 t ADT: 1,410

150TH ST

Fair

Over: BR KITTY CREEK

085032801, Jones, IA

Built 2001 Load: 33.0 t ADT: 15

IA 21

Fair

Over: SOUTH SKUNK RIVER

1.0 mi. S of SR G-48, Keokuk, IA

Built 1989 Load: 33.0 t ADT: 630

FM 170TH ST

Fair

Over: FOUR MILE CREEK

095293401, Kossuth, IA

Built 1975 Load: 33.0 t ADT: 249

LOC 460TH ST

Fair

Over: W BR BLUE EARTH RIVER

099290103, Kossuth, IA

Built 1978 Load: 33.0 t ADT: 41

E CEMETERY RD

Fair

Over: TRIB TO PRAIRIE CREEK

082081111, Linn, IA

Built 1981 Load: 33.0 t ADT: 187

OTIS RD

Fair

Over: INDIAN CREEK

083063017, Linn, IA

Built 2006 Load: 33.0 t ADT: 353

LOCAL

Fair

Over: SMALL STREAM

075032903, Louisa, IA

Built 1978 Load: 33.0 t ADT: 50

FM

Fair

Over: COON CREEK

075210401, Marion, IA

Built 1982 Load: 33.0 t ADT: 40

FM

Fair

Over: DAVISONS CREEK

083172601, Marshall, IA

Built 1979 Load: 33.0 t ADT: 39

FM

Fair

Over: MIDDLE TIMBER CREEK

083183302, Marshall, IA

Built 1979 Load: 33.0 t ADT: 108

SHARP STREET

Fair

Over: KEG CREEK

000000000, Mills, IA

Built 1960 Load: 33.0 t ADT: 3,979

LOCAL

Fair

Over: DD #98

094331302, Palo Alto, IA

Built 1987 Load: 33.0 t ADT: 62

LOCAL

Fair

Over: DD#63

094331901, Palo Alto, IA

Built 1984 Load: 33.0 t ADT: 26

Showing 7,151-7,200 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.