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: N FORK FLOYD RIVER

098413401, Osceola, IA

Built 1969 Load: 20.1 t ADT: 190

LOCAL

Fair

Over: STREAM

100402502, Osceola, IA

Built 1965 Load: 20.1 t ADT: 174

NB US 75

Fair

Over: DRAINAGE DITCH

2.6 mi. S of SR C44, Plymouth, IA

Built 1972 Load: 20.1 t ADT: 7,000

LOCAL

Fair

Over: BIG CEDAR CREEK

090340104, Pocahontas, IA

Built 1942 Load: 20.1 t ADT: 20

WESTERN HILLS D

Fair

Over: WESTERN HILLS CREEK

000000000, Polk, IA

Built 1994 Load: 20.1 t ADT: 716

LOCAL

Fair

Over: BONNIE CREEK

079372203, Shelby, IA

Built 1957 Load: 20.1 t ADT: 51

LOCAL

Fair

Over: KEG CREEK

079390403, Shelby, IA

Built 1956 Load: 20.1 t ADT: 21

LOCAL

Fair

Over: SMALL STREAM

079393102, Shelby, IA

Built 1957 Load: 20.1 t ADT: 35

LOCAL

Fair

Over: SMALL STREAM

079393102, Shelby, IA

Built 1957 Load: 20.1 t ADT: 35

LOCAL

Fair

Over: SMALL STREAM

081370303, Shelby, IA

Built 1954 Load: 20.1 t ADT: 26

LAC-KEO ST PARK

Fair

Over: STREAM

0.8 mi. S of Jct. IA 1, Van Buren, IA

Built 1920 Load: 20.1 t

FM

Fair

Over: SMALL STREAM

074230701, Warren, IA

Built 1948 Load: 20.1 t ADT: 100

LOCAL ROAD

Fair

Over: CREEK

099101002, Winneshiek, IA

Built 1900 Load: 20.1 t ADT: 15

LOCAL

Fair

Over: SPRING BRANCH

083340804, Carroll, IA

Built 1966 Load: 20.2 t ADT: 71

LOCAL

Fair

Over: FIELD STREAM

083343402, Carroll, IA

Built 1967 Load: 20.2 t ADT: 29

LOCAL

Fair

Over: DOE BRANCH CREEK

084332301, Carroll, IA

Built 1965 Load: 20.2 t ADT: 71

LOCAL - FAYETTE

Fair

Over: INDIAN CREEK

077373203, Cass, IA

Built 1974 Load: 20.2 t ADT: 26

190 TH / E33

Fair

Over: DRAINAGE DITCH 430

084312001, Greene, IA

Built 1959 Load: 20.2 t ADT: 199

LOCAL

Fair

Over: LITTLE CEDAR CREEK

070072001, Henry, IA

Built 1957 Load: 20.2 t ADT: 47

LOCAL ROBIN AVE

Fair

Over: SMALL STREAM

099121302, Howard, IA

Built 1984 Load: 20.2 t ADT: 135

FM

Fair

Over: MAPLE RIVER

086410803, Ida, IA

Built 1972 Load: 20.2 t ADT: 71

FM

Fair

Over: MAPLE RIVER

089391001, Ida, IA

Built 1973 Load: 20.2 t ADT: 34

LOCAL

Fair

Over: IOWA SLOUGH

073013206, Louisa, IA

Built 1978 Load: 20.2 t ADT: 40

IA 14

Fair

Over: DES MOINES RIVER & RES

1.2 MI. N OF SR G40, Marion, IA

Built 1965 Load: 20.2 t ADT: 3,820

LOCAL

Fair

Over: NODAWAY TRIB

071361206, Montgomery, IA

Built 1961 Load: 20.2 t ADT: 26

LOCAL

Fair

Over: LOCAL CREEK

071373304, Montgomery, IA

Built 1992 Load: 20.2 t ADT: 34

LOCAL

Fair

Over: HARVEY DITCH

077040204, Muscatine, IA

Built 1937 Load: 20.2 t ADT: 45

LOCAL

Fair

Over: OTTER CREEK

083140602, Tama, IA

Built 1965 Load: 20.2 t ADT: 39

LOCAL

Fair

Over: WOLF CREEK

083141202, Tama, IA

Built 1965 Load: 20.2 t ADT: 20

LOCAL

Fair

Over: BUSHY CREEK

067352406, Taylor, IA

Built 1995 Load: 20.2 t ADT: 11

LOCAL ROAD

Fair

Over: SOUTH RIVER

074250103, Warren, IA

Built 1973 Load: 20.2 t ADT: 30

LOCAL

Fair

Over: SMALL CREEK

077240200, Warren, IA

Built 1980 Load: 20.2 t ADT: 875

LOCAL

Fair

Over: BRANCH NORTH RIVER

077241502, Warren, IA

Built 1984 Load: 20.2 t ADT: 150

LOCAL ROAD

Fair

Over: SMALL CREEK

074062205, Washington, IA

Built 1964 Load: 20.2 t ADT: 30

FM

Fair

Over: CREEK

093260901, Wright, IA

Built 1980 Load: 20.2 t ADT: 42

LOCAL

Fair

Over: BEAVER CREEK

090172402, Butler, IA

Built 1952 Load: 20.3 t ADT: 51

FM- 610TH ST

Fair

Over: ROCK CREEK

090410901, Cherokee, IA

Built 1976 Load: 20.3 t ADT: 259

FM - 650TH ST

Fair

Over: N OIERSON CREEK

090423301, Cherokee, IA

Built 1974 Load: 20.3 t ADT: 350

LOCAL

Fair

Over: MIDDLE SOLDIER RIVER

085413601, Crawford, IA

Built 2002 Load: 20.3 t ADT: 15

LOCAL

Fair

Over: SLOUGH

080270301, Dallas, IA

Built 1925 Load: 20.3 t ADT: 35

LOCAL

Fair

Over: SOUTH FORK

089220607, Hardin, IA

Built 1981 Load: 20.3 t ADT: 16

FM & 270TH ST

Fair

Over: PIGEON CREEK

079413301, Harrison, IA

Built 1951 Load: 20.3 t ADT: 20

LOCAL

Fair

Over: DEER CREEK

078091204, Iowa, IA

Built 1942 Load: 20.3 t ADT: 40

LOCAL

Fair

Over: DRAINAGE

077292502, Madison, IA

Built 1960 Load: 20.3 t ADT: 26

LOCAL

Fair

Over: DRAINAGE

078030905, Muscatine, IA

Built 1947 Load: 20.3 t ADT: 26

B AVENUE

Fair

Over: WEST TARKIO CREEK

067392902, Page, IA

Built 1995 Load: 20.3 t ADT: 26

367TH

Fair

Over: STREAM

098192003, Worth, IA

Built 1959 Load: 20.3 t ADT: 25

LOCAL

Fair

Over: BRANCH NORTH RIVER

076300202, Adair, IA

Built 1966 Load: 20.4 t ADT: 30

120TH STREET

Fair

Over: SHANGHAI CREEK

073321503, Adams, IA

Built 1980 Load: 20.4 t ADT: 11

FM

Fair

Over: BRANCH YELLOW RIVER

096060306, Allamakee, IA

Built 1959 Load: 20.4 t ADT: 422

Showing 2,651-2,700 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.