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

Fair

Over: MILLER CREEK

084373302, Crawford, IA

Built 2003 Load: 17.8 t ADT: 30

COUNTY ROAD

Fair

Over: PANTHER CREEK

079283401, Dallas, IA

Built 1953 Load: 17.8 t ADT: 60

FM

Fair

Over: FLINT RIVER

071042304, Des Moines, IA

Built 1941 Load: 17.8 t ADT: 130

307 AVENUE

Fair

Over: CAMP CREEK

070413106, Fremont, IA

Built 1975 Load: 17.8 t ADT: 34

IA 44

Fair

Over: BRANCH MOSQUITO CREEK

3.6 mi. E of jct. IA 4, Guthrie, IA

Built 1981 Load: 17.8 t ADT: 3,460

LOCAL

Fair

Over: SMALL STREAM

089221701, Hardin, IA

Built 1987 Load: 17.8 t ADT: 26

SPENCER ST

Fair

Over: S SKUNK RIVER

078183002, Jasper, IA

Built 1954 Load: 17.8 t ADT: 50

FM

Fair

Over: SMALL STREAM

065052009, Lee, IA

Built 1958 Load: 17.8 t ADT: 180

LOCAL

Fair

Over: BR LITTLE WHITEBREAST CK

073222305, Lucas, IA

Built 2010 Load: 17.8 t ADT: 5

LOCAL RD

Fair

Over: DRAINAGE

074291201, Madison, IA

Built 1977 Load: 17.8 t ADT: 20

LOCAL

Fair

Over: ENGELS CREEK

097421302, O'Brien, IA

Built 1932 Load: 17.8 t ADT: 21

LOCAL

Fair

Over: DRAINAGE DITCH #42

098410401, Osceola, IA

Built 1940 Load: 17.8 t ADT: 21

LOCAL

Fair

Over: OCHEYEDAN RIVER

100403101, Osceola, IA

Built 1949 Load: 17.8 t ADT: 30

LOCAL

Fair

Over: SNOW CREEK

100421604, Osceola, IA

Built 1935 Load: 17.8 t ADT: 15

FM

Fair

Over: KOOLMAN CREEK

100421702, Osceola, IA

Built 1938 Load: 17.8 t ADT: 34

FM

Fair

Over: LOTTS CREEK

069282902, Ringgold, IA

Built 1966 Load: 17.8 t ADT: 159

265TH AVE

Fair

Over: CREEK

080E52804, Scott, IA

Built 1965 Load: 17.8 t ADT: 20

FM

Fair

Over: SILVER CREEK

079393404, Shelby, IA

Built 1959 Load: 17.8 t ADT: 29

LOCAL

Fair

Over: KEG CREEK

079402502, Shelby, IA

Built 1958 Load: 17.8 t ADT: 30

LOCAL

Fair

Over: SMALL STREAM

079403602, Shelby, IA

Built 1958 Load: 17.8 t ADT: 35

FM RD F16

Fair

Over: WILLOW CREEK

081391001, Shelby, IA

Built 1958 Load: 17.8 t ADT: 60

120TH ST

Fair

Over: HAMILTON-STORY 1 OPEN DD

085241501, Story, IA

Built 1940 Load: 17.8 t ADT: 50

LOCAL

Fair

Over: CREEK

069112107, Van Buren, IA

Built 1965 Load: 17.8 t ADT: 30

LOCAL

Fair

Over: STREAM

068182501, Appanoose, IA

Built 1992 Load: 17.9 t ADT: 73

FM

Fair

Over: BR ELKHORN CREEK

079353102, Audubon, IA

Built 1967 Load: 17.9 t ADT: 15

FM

Fair

Over: BEAVER CREEK

084282101, Boone, IA

Built 1923 Load: 17.9 t ADT: 20

270TH ST

Fair

Over: QUARTER SECTION RUN

091133501, Bremer, IA

Built 1951 Load: 17.9 t ADT: 118

LOCAL

Fair

Over: FIELD STREAM

083341002, Carroll, IA

Built 1961 Load: 17.9 t ADT: 89

LOCAL

Fair

Over: BRUSHY FORK CREEK

083352104, Carroll, IA

Built 1962 Load: 17.9 t ADT: 71

LOCAL

Fair

Over: FIELD STREAM

085363202, Carroll, IA

Built 1971 Load: 17.9 t ADT: 50

LOCAL

Fair

Over: EMIGRANT CREEK

084403004, Crawford, IA

Built 1985 Load: 17.9 t ADT: 21

LOCAL

Fair

Over: ACKLEY CREEK

094181402, Floyd, IA

Built 1999 Load: 17.9 t ADT: 44

330 TH

Fair

Over: STREAM

082293501, Greene, IA

Built 1921 Load: 17.9 t ADT: 26

FM NEWARK AVE

Fair

Over: ALLEN CREEK

081431302, Harrison, IA

Built 1960 Load: 17.9 t ADT: 5

NOBLE AVE

Fair

Over: BRANCH UPPER IOWA RIVER

100120804, Howard, IA

Built 1985 Load: 17.9 t ADT: 26

I 80

Fair

Over: STREAM

0.7 MI. E OF Jct. US 151, Iowa, IA

Built 1963 Load: 17.9 t ADT: 32,400

LOMBARDY ROAD

Fair

Over: SECOND CREEK

076392703, Pottawattamie, IA

Built 1953 Load: 17.9 t ADT: 20

LOCAL

Fair

Over: STREAM

067301604, Ringgold, IA

Built 2002 Load: 17.9 t ADT: 11

LOCAL

Fair

Over: TWELVE MILE CREEK

086142803, Tama, IA

Built 1950 Load: 17.9 t ADT: 29

FM

Fair

Over: MIDDLE BRANCH 102 RIVER

070332104, Taylor, IA

Built 1949 Load: 17.9 t ADT: 50

SWIFT AVE

Fair

Over: CREEK

078340204, Audubon, IA

Built 1945 Load: 18.0 t ADT: 35

FM

Fair

Over: BR NISHNABOTNA RIVER

079352701, Audubon, IA

Built 1963 Load: 18.0 t ADT: 34

LOCAL

Fair

Over: STREAM

081351301, Audubon, IA

Built 1941 Load: 18.0 t ADT: 40

FM

Fair

Over: BEAVER CREEK

083282201, Boone, IA

Built 1924 Load: 18.0 t ADT: 15

110TH

Fair

Over: W BRANCH BEAVER DAM CRK

094213301, Cerro Gordo, IA

Built 1960 Load: 18.0 t ADT: 11

250TH

Fair

Over: LITTLE LIME CREEK

096192101, Cerro Gordo, IA

Built 1959 Load: 18.0 t ADT: 30

LOCAL 470TH ST

Fair

Over: MILL CREEK

093403201, Cherokee, IA

Built 1974 Load: 18.0 t ADT: 71

HORSESHOE RD

Fair

Over: ELK CREEK

091042607, Clayton, IA

Built 1939 Load: 18.0 t ADT: 79

LOCAL

Fair

Over: SMALL STREAM

082372102, Crawford, IA

Built 2007 Load: 18.0 t ADT: 46

LOCAL

Fair

Over: SMALL STREAM

082411801, Crawford, IA

Built 1996 Load: 18.0 t ADT: 15

Showing 2,001-2,050 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.