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

LOCAL

Poor

Over: BRANCH OLD MANS CREEK

079093002, Iowa, IA

Built 1930 Load: 19.3 t ADT: 50

WINSLOW RD

Poor

Over: INDIAN CREEK

084063000, Linn, IA

Built 2002 Load: 19.3 t ADT: 1,129

FM

Poor

Over: BURNETT CREEK

084170301, Marshall, IA

Built 1921 Load: 19.3 t ADT: 69

LOCAL

Poor

Over: ROCK CR

084171402, Marshall, IA

Built 1950 Load: 19.3 t ADT: 30

LOCAL

Poor

Over: BR MINERVA CR

084191502, Marshall, IA

Built 1947 Load: 19.3 t ADT: 16

FM-310TH STREET

Poor

Over: IAIS RR

076412002, Pottawattamie, IA

Built 1952 Load: 19.3 t ADT: 110

SUMAC ROAD

Poor

Over: STREAM

077383101, Pottawattamie, IA

Built 1992 Load: 19.3 t ADT: 11

115TH ST

Poor

Over: BEAR CREEK

085231103, Story, IA

Built 1955 Load: 19.3 t ADT: 120

LOCAL

Poor

Over: WOLF CREEK

073282006, Union, IA

Built 1983 Load: 19.3 t ADT: 21

LOCAL ROAD

Poor

Over: PAINTER CREEK

075252205, Warren, IA

Built 1947 Load: 19.3 t ADT: 35

FM

Poor

Over: SMALL STREAM

076082104, Washington, IA

Built 1917 Load: 19.3 t ADT: 50

LOCAL

Poor

Over: BEAVER CREEK

098230101, Winnebago, IA

Built 1985 Load: 19.3 t ADT: 35

LOCAL

Poor

Over: SOAP CR

070141604, Davis, IA

Built 1958 Load: 19.4 t ADT: 34

LOCAL

Poor

Over: SMALL

081332004, Guthrie, IA

Built 1980 Load: 19.4 t ADT: 26

CENTER PT.RD.

Poor

Over: EAST OTTER CK

084070614, Linn, IA

Built 1956 Load: 19.4 t ADT: 5,401

LOCAL SEC RD

Poor

Over: GINGER CR

094400601, O'Brien, IA

Built 1900 Load: 19.4 t ADT: 15

LOCAL

Poor

Over: STREAM

095310102, Palo Alto, IA

Built 1925 Load: 19.4 t ADT: 46

FM

Poor

Over: TRIB DES MOINES R

068081605, Van Buren, IA

Built 1969 Load: 19.4 t ADT: 50

FM

Poor

Over: CHEQUEST CREEK

069112004, Van Buren, IA

Built 1953 Load: 19.4 t ADT: 20

LOCAL

Poor

Over: MIDDLE RIVER

076302603, Adair, IA

Built 1968 Load: 19.5 t ADT: 15

LOCAL

Poor

Over: SMALL STREAM

090170302, Butler, IA

Built 1953 Load: 19.5 t ADT: 35

195TH ST

Poor

Over: STREAM

092151903, Butler, IA

Built 1900 Load: 19.5 t ADT: 73

205TH ST

Poor

Over: ROCK CR

081012903, Cedar, IA

Built 1917 Load: 19.5 t ADT: 15

FM

Poor

Over: BR LITTLE WAPSIPINICON

096133001, Chickasaw, IA

Built 1957 Load: 19.5 t ADT: 118

LOCAL

Poor

Over: SMALL STREAM

081190602, Jasper, IA

Built 1974 Load: 19.5 t ADT: 35

LOCAL

Poor

Over: DRAINAGE

075291408, Madison, IA

Built 1938 Load: 19.5 t ADT: 20

LOCAL

Poor

Over: STREAM

075193203, Marion, IA

Built 1953 Load: 19.5 t ADT: 30

LOCAL

Poor

Over: CREEK

085193604, Marshall, IA

Built 1947 Load: 19.5 t ADT: 21

FM

Poor

Over: AVERY CREEK

071161103, Monroe, IA

Built 1970 Load: 19.5 t ADT: 80

LOCAL

Poor

Over: DRAINAGE

073191302, Monroe, IA

Built 1996 Load: 19.5 t ADT: 11

FM

Poor

Over: MOON CREEK

078152207, Poweshiek, IA

Built 1952 Load: 19.5 t ADT: 30

LOCAL

Poor

Over: SMALL STREAM

089351101, Sac, IA

Built 1923 Load: 19.5 t ADT: 15

590TH AVE

Poor

Over: GRANT 5 OPEN DITCH

083231002, Story, IA

Built 1938 Load: 19.5 t ADT: 230

LOCAL

Poor

Over: PACKARD CREEK

067170206, Appanoose, IA

Built 1900 Load: 19.6 t ADT: 16

LOCAL

Poor

Over: MUD CREEK

084112304, Benton, IA

Built 1983 Load: 19.6 t ADT: 26

ECHO VALLEY RD

Poor

Over: UNAMED CR

094072003, Fayette, IA

Built 1964 Load: 19.6 t ADT: 78

FM

Poor

Over: WALNUT CREEK

073380901, Montgomery, IA

Built 1956 Load: 19.6 t ADT: 528

FM

Poor

Over: WATERMAN CREEK

097401201, O'Brien, IA

Built 2003 Load: 19.6 t ADT: 34

LOCAL

Poor

Over: CAMP CREEK

079223503, Polk, IA

Built 1959 Load: 19.6 t ADT: 34

390TH STREET

Poor

Over: IAIS RR

076402202, Pottawattamie, IA

Built 1952 Load: 19.6 t ADT: 11

BALSAM

Poor

Over: BEAVER CREEK

098222904, Worth, IA

Built 1977 Load: 19.6 t ADT: 216

FM

Poor

Over: BR LITTLE TURKEY RIVER

097113301, Chickasaw, IA

Built 1965 Load: 19.7 t ADT: 511

LOCAL

Poor

Over: SOUTH FORK MIDDLE RIVER

078332602, Guthrie, IA

Built 1971 Load: 19.7 t ADT: 40

LOCAL

Poor

Over: BRANCH N SKUNK RIVER

082202401, Marshall, IA

Built 1939 Load: 19.7 t ADT: 10

FM

Poor

Over: CREEK

085202603, Marshall, IA

Built 1963 Load: 19.7 t ADT: 29

LOCAL

Poor

Over: STREAM

069290701, Ringgold, IA

Built 1930 Load: 19.7 t ADT: 15

LOCAL

Poor

Over: SMALL

067352404, Taylor, IA

Built 1983 Load: 19.7 t ADT: 26

LOCAL

Poor

Over: DD

089270301, Webster, IA

Built 1976 Load: 19.7 t ADT: 15

FM

Poor

Over: DRAINAGE DITCH

088242301, Hamilton, IA

Built 1923 Load: 19.8 t ADT: 26

LOCAL

Poor

Over: SUGAR CREEK

069060604, Lee, IA

Built 1929 Load: 19.8 t ADT: 30

Showing 17,951-18,000 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.