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

Poor

Over: ROCK RIVER

096471603, Sioux, IA

Built 1952 Load: 28.5 t ADT: 1,017

FM

Poor

Over: RACCOON RIVER

091363601, Buena Vista, IA

Built 1976 Load: 28.6 t ADT: 1,228

FM

Poor

Over: DRY BRANCH

070022103, Des Moines, IA

Built 1970 Load: 28.6 t ADT: 240

FM

Poor

Over: FLOOD CREEK

096171906, Floyd, IA

Built 1975 Load: 28.6 t ADT: 491

1350 170TH ST

Poor

Over: WEST IOWA RIVER

095243101, Hancock, IA

Built 1979 Load: 28.6 t ADT: 569

FM

Poor

Over: SOLDIER RIVER

086403101, Ida, IA

Built 1971 Load: 28.6 t ADT: 350

FM

Poor

Over: LITTLE WHITEBREAST CREEK

072211509, Lucas, IA

Built 1974 Load: 28.6 t ADT: 490

FM

Poor

Over: INDIAN CREEK

080202901, Jasper, IA

Built 1951 Load: 28.7 t ADT: 150

W MAIN ST

Poor

Over: SMALL NATURAL STREAM

074222801, Warren, IA

Built 1959 Load: 28.7 t ADT: 643

VIKING AV

Poor

Over: BUCK CREEK

092113402, Bremer, IA

Built 1958 Load: 28.8 t ADT: 854

FM

Poor

Over: LITTLE BEAR CREEK

080110903, Iowa, IA

Built 1975 Load: 28.8 t ADT: 25

LOCAL ROAD

Poor

Over: RAT CREEK

098432801, Lyon, IA

Built 1900 Load: 28.8 t ADT: 21

LOCAL

Poor

Over: DRAINAGE

076290402, Madison, IA

Built 1952 Load: 28.8 t ADT: 15

FM

Poor

Over: INDIAN CREEK

073390901, Montgomery, IA

Built 1957 Load: 28.8 t ADT: 270

LOCAL

Poor

Over: MID FK GRAND RIVER

067302001, Ringgold, IA

Built 1988 Load: 28.8 t ADT: 45

LOCAL

Poor

Over: BIG CREEK

083252901, Boone, IA

Built 1915 Load: 29.0 t ADT: 50

FM

Poor

Over: CAIN CREEK

088340103, Calhoun, IA

Built 1971 Load: 29.0 t ADT: 110

FM

Poor

Over: KNOTTY CREEK

070032405, Des Moines, IA

Built 1980 Load: 29.0 t ADT: 1,000

FM

Poor

Over: TIPTON CR

087212202, Hardin, IA

Built 1974 Load: 29.0 t ADT: 687

LCL-ALLIS RD

Poor

Over: STREAM

073441304, Mills, IA

Built 1978 Load: 29.0 t ADT: 89

FM

Poor

Over: BUSHY CREEK

067351301, Taylor, IA

Built 1986 Load: 29.0 t ADT: 210

FM-MAGNOLIA RD

Poor

Over: MOSQUITO CREEK

076422103, Pottawattamie, IA

Built 1965 Load: 29.1 t ADT: 2,949

LOCAL

Poor

Over: CREEK

096082206, Winneshiek, IA

Built 1900 Load: 29.2 t ADT: 97

LOCAL

Poor

Over: STREAM

069170603, Appanoose, IA

Built 1900 Load: 29.3 t ADT: 11

FM

Poor

Over: DES MOINES RIVER

083262905, Boone, IA

Built 1972 Load: 29.3 t ADT: 769

LOCAL

Poor

Over: DRAINAGE DITCH

098260401, Winnebago, IA

Built 1985 Load: 29.3 t ADT: 26

150TH ST

Poor

Over: BROKEN KETTLE CREEK

093473501, Plymouth, IA

Built 1952 Load: 29.4 t ADT: 11

IRR-FM

Poor

Over: IOWA RIVER

083153007, Tama, IA

Built 1988 Load: 29.4 t ADT: 619

IA 23

Poor

Over: TRIBUTARY OF CEDAR CREEK

0.8 MI. N 0F Jct. SR T67, Mahaska, IA

Built 1928 Load: 29.5 t ADT: 2,350

LOCAL

Poor

Over: TWELVE MILE CREEK

073300701, Union, IA

Built 1979 Load: 29.5 t ADT: 62

FM

Poor

Over: ROCK CK

085120701, Benton, IA

Built 1958 Load: 29.6 t ADT: 30

FM 300TH ST

Poor

Over: BIG MUDDY CREEK

097362301, Clay, IA

Built 1963 Load: 29.7 t ADT: 369

LOCAL

Poor

Over: SPRING CREEK

075150404, Mahaska, IA

Built 1948 Load: 29.7 t ADT: 71

LOCAL RD

Poor

Over: TIMBER CREEK

083182410, Marshall, IA

Built 1977 Load: 29.7 t ADT: 227

IA 141 & 175

Poor

Over: MAPLE RIVER

0.1 mi. E of W jct IA 175, Monona, IA

Built 1967 Load: 29.7 t ADT: 3,640

IA 10

Poor

Over: MUD CREEK

1.9 mi W of SR L48, O'Brien, IA

Built 1951 Load: 29.7 t ADT: 1,740

FM

Poor

Over: CEDAR RIVER

085091106, Benton, IA

Built 1969 Load: 29.8 t ADT: 1,267

FM

Poor

Over: LITTLE CEDAR RIVER

096151602, Floyd, IA

Built 1974 Load: 29.8 t ADT: 1,414

FM

Poor

Over: WAPSINONOC CREEK

078041407, Muscatine, IA

Built 1981 Load: 29.8 t ADT: 1,510

FM

Poor

Over: SMALL STREAM

077090708, Washington, IA

Built 1927 Load: 29.8 t ADT: 45

FM

Poor

Over: BR ENGLISH RIVER

077091703, Washington, IA

Built 1927 Load: 29.8 t ADT: 40

FM

Poor

Over: TRIBUTARY BEAVER CREEK

084283202, Boone, IA

Built 1962 Load: 29.9 t ADT: 80

190TH ST

Poor

Over: BASKINS CREEK

092131901, Bremer, IA

Built 1971 Load: 29.9 t ADT: 1,149

FM

Poor

Over: MOSQUITO CREEK

087152902, Grundy, IA

Built 1977 Load: 29.9 t ADT: 501

FM

Poor

Over: BLACKHAWK CREEK

088173602, Grundy, IA

Built 1971 Load: 29.9 t ADT: 1,935

320TH

Poor

Over: FISH CREEK

097161301, Mitchell, IA

Built 1965 Load: 29.9 t ADT: 226

FM

Poor

Over: BEAR CREEK

080140902, Poweshiek, IA

Built 1979 Load: 29.9 t ADT: 130

OLIVE

Poor

Over: DRAINAGE DITCH

098202804, Worth, IA

Built 1974 Load: 29.9 t ADT: 51

FM

Poor

Over: WHITE FOX CREEK

091243101, Wright, IA

Built 1963 Load: 29.9 t ADT: 742

FM

Poor

Over: ROCK CREEK

086122401, Benton, IA

Built 1985 Load: 30.0 t ADT: 430

Showing 18,851-18,900 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.