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

THRUSH

Fair

Over: CREEK

096193202, Cerro Gordo, IA

Built 1932 Load: 24.2 t ADT: 903

KILLDEER

Fair

Over: CRANE CREEK

096211404, Cerro Gordo, IA

Built 1973 Load: 24.2 t ADT: 361

315TH

Fair

Over: ROCK FALLS CREEK

097191503, Cerro Gordo, IA

Built 1924 Load: 24.2 t ADT: 62

FM

Fair

Over: CHARITON CREEK

071252504, Clarke, IA

Built 1981 Load: 24.2 t ADT: 40

ST SEBALD RD

Fair

Over: STREAM

092062303, Clayton, IA

Built 1939 Load: 24.2 t ADT: 39

90TH ST.

Fair

Over: OTTER CREEK

092093001, Fayette, IA

Built 1995 Load: 24.2 t ADT: 33

US 18

Fair

Over: BOONE RIVER

4.7 mi. W of Jct. SR R35, Hancock, IA

Built 1959 Load: 24.2 t ADT: 2,980

LOCAL

Fair

Over: CEDAR CREEK

076133602, Keokuk, IA

Built 1976 Load: 24.2 t ADT: 90

LOCAL RD

Fair

Over: MIDDLE RIVER

076293102, Madison, IA

Built 1959 Load: 24.2 t ADT: 40

IA 316

Fair

Over: NS & BNSF RR

2.4 Mi. N of IA 5, Marion, IA

Built 1967 Load: 24.2 t ADT: 990

FM C-60

Fair

Over: WEST FORK LITTLE SIOUX

090431001, Plymouth, IA

Built 1963 Load: 24.2 t ADT: 290

FM

Fair

Over: PONY CREEK

074431503, Pottawattamie, IA

Built 1966 Load: 24.2 t ADT: 1,733

14TH AVE

Fair

Over: INDIAN CREEK

000000000, Pottawattamie, IA

Built 1935 Load: 24.2 t ADT: 546

LOCAL

Fair

Over: BRANCH CRYSTAL CREEK

084150602, Tama, IA

Built 1945 Load: 24.2 t ADT: 15

FM

Fair

Over: FOUR MILE CREEK

073282402, Union, IA

Built 1950 Load: 24.2 t ADT: 20

IA 7

Fair

Over: SOUTH BR LIZARD CREEK

0.8 mi. E of W Jct SR P29, Webster, IA

Built 1974 Load: 24.2 t ADT: 2,560

LOCAL

Fair

Over: MIDDLE RIVER

076302706, Adair, IA

Built 1950 Load: 24.3 t ADT: 30

WILLOW AVENUE

Fair

Over: PLATTE RIVER

072323604, Adams, IA

Built 1965 Load: 24.3 t ADT: 26

LOCAL

Fair

Over: STREAM

069190405, Appanoose, IA

Built 1998 Load: 24.3 t ADT: 11

FM

Fair

Over: STREAM

089102802, Buchanan, IA

Built 1951 Load: 24.3 t ADT: 147

LOCAL

Fair

Over: FIELD STREAM

082340602, Carroll, IA

Built 1950 Load: 24.3 t ADT: 60

ESSEX RD

Fair

Over: ROBERTS CREEK

094051504, Clayton, IA

Built 1917 Load: 24.3 t ADT: 16

FM

Fair

Over: MIDDLE WILLOW CREEK

083412801, Crawford, IA

Built 1958 Load: 24.3 t ADT: 40

FM 190 AVE

Fair

Over: BUCK CREEK

087051502, Delaware, IA

Built 1969 Load: 24.3 t ADT: 157

FM

Fair

Over: CREEK

089E13006, Dubuque, IA

Built 1975 Load: 24.3 t ADT: 462

INDIGO AVE

Fair

Over: MAYNES CR

091211602, Franklin, IA

Built 1959 Load: 24.3 t ADT: 21

FM JONQUIL AVE

Fair

Over: MAYNES CREEK

091212202, Franklin, IA

Built 1960 Load: 24.3 t ADT: 34

IA 2

Fair

Over: DRAINAGE DITCH

2.8 MI. E OF JCT. IA 29, Fremont, IA

Built 1953 Load: 24.3 t ADT: 1,630

280 STREET

Fair

Over: MILL CREEK

067410903, Fremont, IA

Built 1961 Load: 24.3 t ADT: 30

FM

Fair

Over: SMALL

078321702, Guthrie, IA

Built 1979 Load: 24.3 t ADT: 71

720 130TH ST

Fair

Over: DD #159

094252001, Hancock, IA

Built 1958 Load: 24.3 t ADT: 41

B-62

Fair

Over: W OTTER CREEK DD 26

094252201, Hancock, IA

Built 1959 Load: 24.3 t ADT: 42

3180 MAPLE AVE

Fair

Over: DD 1&2

097241802, Hancock, IA

Built 1958 Load: 24.3 t ADT: 31

FM

Fair

Over: CREEK

087191404, Hardin, IA

Built 1988 Load: 24.3 t ADT: 39

FM OVERTON AVE

Fair

Over: HARRIS GROVE CREEK

078430308, Harrison, IA

Built 1963 Load: 24.3 t ADT: 788

LOCAL ROAD

Fair

Over: CREEK

086401301, Ida, IA

Built 2001 Load: 24.3 t ADT: 11

FM

Fair

Over: MAQUOKETA RIVER

084E41306, Jackson, IA

Built 1964 Load: 24.3 t ADT: 430

LOCAL

Fair

Over: CREEK

084E51507, Jackson, IA

Built 1978 Load: 24.3 t ADT: 90

LOCAL

Fair

Over: TURKEY CREEK

080200504, Jasper, IA

Built 1996 Load: 24.3 t ADT: 62

20TH ST.

Fair

Over: WHITE OAK CREEK

083043501, Jones, IA

Built 1985 Load: 24.3 t ADT: 11

SPRINGVILLE RD

Fair

Over: ABBE CREEK

082050302, Linn, IA

Built 1960 Load: 24.3 t ADT: 845

FM

Fair

Over: OVERFLOW N.RIVER

077273602, Madison, IA

Built 1961 Load: 24.3 t ADT: 50

FA-PADDOCK AVE

Fair

Over: DEER CREEK

071402001, Mills, IA

Built 1958 Load: 24.3 t ADT: 40

FA-310TH ST

Fair

Over: SPRING VALLEY CREEK

071413202, Mills, IA

Built 1960 Load: 24.3 t ADT: 319

FM

Fair

Over: SIN CREEK

073362301, Montgomery, IA

Built 1959 Load: 24.3 t ADT: 45

ORIOLE AVE

Fair

Over: OTTER CREEK

100413002, Osceola, IA

Built 1956 Load: 24.3 t ADT: 230

300TH STREET

Fair

Over: STREAM

067372401, Page, IA

Built 1962 Load: 24.3 t ADT: 34

FM

Fair

Over: DD #81

095322504, Palo Alto, IA

Built 1982 Load: 24.3 t ADT: 41

E LINCOLN WAY

Fair

Over: SKUNK RIVER

A16050635, Story, IA

Built 1952 Load: 24.3 t ADT: 9,468

IA 21

Fair

Over: DRAINAGE DITCH

0.3 MILE N OF N JCT IA 8, Tama, IA

Built 1960 Load: 24.3 t ADT: 2,600

Showing 3,851-3,900 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.