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: OLD MANS CREEK

079103602, Iowa, IA

Built 1978 Load: 20.0 t ADT: 34

S 120TH AVE E

Fair

Over: SMALL STREAM

078173205, Jasper, IA

Built 1988 Load: 20.0 t ADT: 26

LOC 385TH ST

Fair

Over: E FORK DES MOINES RIVER

098300805, Kossuth, IA

Built 1978 Load: 20.0 t ADT: 26

LOCAL

Fair

Over: BR OF LITTLE WHITEBREAST

072213504, Lucas, IA

Built 1960 Load: 20.0 t ADT: 11

IA 9

Fair

Over: MOON CREEK

0.3 mi. W of W jct. US 75, Lyon, IA

Built 1974 Load: 20.0 t ADT: 3,180

LOCAL ROAD

Fair

Over: MUD CREEK

098461601, Lyon, IA

Built 1900 Load: 20.0 t ADT: 49

LOCAL ROAD

Fair

Over: MUD CREEK

099462901, Lyon, IA

Built 1971 Load: 20.0 t ADT: 26

LOCAL ROAD

Fair

Over: MUD CREEK

099463201, Lyon, IA

Built 1971 Load: 20.0 t ADT: 30

FM

Fair

Over: S FORK CLANTON CREEK

074272204, Madison, IA

Built 1979 Load: 20.0 t ADT: 60

LOCAL RD

Fair

Over: CLANTON CREEK

075262702, Madison, IA

Built 1978 Load: 20.0 t ADT: 40

FM

Fair

Over: NORTH RIVER

076281802, Madison, IA

Built 1949 Load: 20.0 t ADT: 477

FM

Fair

Over: DRAINAGE #42

098410302, Osceola, IA

Built 1934 Load: 20.0 t ADT: 40

LOCAL

Fair

Over: LIZARD CK

090310102, Pocahontas, IA

Built 1966 Load: 20.0 t ADT: 45

LOCAL

Fair

Over: MINOR DRAINAGE

076382101, Pottawattamie, IA

Built 1973 Load: 20.0 t ADT: 20

LOCAL

Fair

Over: SUN VALLEY CREEK

070291902, Ringgold, IA

Built 2003 Load: 20.0 t ADT: 5

75TH AVE

Fair

Over: CREEK

080E22906, Scott, IA

Built 1972 Load: 20.0 t ADT: 15

LOCAL

Fair

Over: SMALL STREAM

078372902, Shelby, IA

Built 1969 Load: 20.0 t ADT: 21

322ND ST

Fair

Over: CALAMUS CREEK

082222903, Story, IA

Built 1916 Load: 20.0 t ADT: 15

295TH ST

Fair

Over: CALAMUS CREEK

082231203, Story, IA

Built 1958 Load: 20.0 t ADT: 30

315TH ST

Fair

Over: DRAINAGE DITCH

082232209, Story, IA

Built 1964 Load: 20.0 t ADT: 30

550TH AVE

Fair

Over: BALLARD CREEK

000000000, Story, IA

Built 1919 Load: 20.0 t ADT: 100

610TH AVE

Fair

Over: DD 32

084233602, Story, IA

Built 1900 Load: 20.0 t ADT: 45

LOCAL

Fair

Over: RICHLAND CREEK

082152604, Tama, IA

Built 1989 Load: 20.0 t ADT: 59

LOCAL

Fair

Over: DEER CREEK

084153405, Tama, IA

Built 1900 Load: 20.0 t ADT: 70

FM

Fair

Over: WOLF CREEK

085151106, Tama, IA

Built 1959 Load: 20.0 t ADT: 59

FM

Fair

Over: PLATTE BRANCH

067330103, Taylor, IA

Built 1976 Load: 20.0 t ADT: 15

FM

Fair

Over: WEST 102 RIVER

069351503, Taylor, IA

Built 1976 Load: 20.0 t ADT: 29

LOCAL

Fair

Over: EAST FORK MEDICINE

068222407, Wayne, IA

Built 1981 Load: 20.0 t ADT: 15

FM

Fair

Over: DRY CREEK

100103002, Winneshiek, IA

Built 1957 Load: 20.0 t ADT: 98

LOCAL

Fair

Over: SOAP CREEK

070171404, Appanoose, IA

Built 1976 Load: 20.1 t ADT: 51

TREMONT ST

Fair

Over: SMALL STREAM

000000000, Black Hawk, IA

Built 1956 Load: 20.1 t ADT: 342

160TH ST

Fair

Over: BUCK CREEK

092110401, Bremer, IA

Built 1960 Load: 20.1 t ADT: 33

NISHNA ST

Fair

Over: SMALL CREEK

000000000, Cass, IA

Built 1983 Load: 20.1 t ADT: 101

FM- V AVE

Fair

Over: SMALL STREAM

090392202, Cherokee, IA

Built 1973 Load: 20.1 t ADT: 60

300TH AVE

Fair

Over: STREAM

088 03 21 02, Delaware, IA

Built 2015 Load: 20.1 t ADT: 33

US 59

Fair

Over: BRANCH SOLDIER RIVER

3.9 mi. S of S jct IA 175, Ida, IA

Built 1947 Load: 20.1 t ADT: 1,130

LOCAL

Fair

Over: SMALL CREEK

084E62804, Jackson, IA

Built 1981 Load: 20.1 t ADT: 11

LOCAL

Fair

Over: CEDAR CREEK

074151304, Mahaska, IA

Built 1963 Load: 20.1 t ADT: 71

LOCAL

Fair

Over: CALHOUN CREEK

077200403, Marion, IA

Built 1961 Load: 20.1 t ADT: 41

LOCAL

Fair

Over: AVERY CREEK

071160703, Monroe, IA

Built 1968 Load: 20.1 t ADT: 60

FM

Fair

Over: MCCREATH CREEK

095390801, O'Brien, IA

Built 1953 Load: 20.1 t ADT: 797

FM

Fair

Over: JORDAN CREEK

095393202, O'Brien, IA

Built 1969 Load: 20.1 t ADT: 948

LOCAL

Fair

Over: GRASS WATERWAY

096410402, O'Brien, IA

Built 1954 Load: 20.1 t ADT: 50

290TH ST

Fair

Over: FLOYD RIVER

097411401, O'Brien, IA

Built 2018 Load: 20.1 t ADT: 26

FM

Fair

Over: SMALL UN-NAMED CREEK

097421201, O'Brien, IA

Built 1969 Load: 20.1 t ADT: 509

FM

Fair

Over: SMALL UN-NAMED CREEK

095410302, O'Brien, IA

Built 1992 Load: 20.1 t ADT: 917

FM

Fair

Over: DRY RUN

098390801, Osceola, IA

Built 1954 Load: 20.1 t ADT: 738

FM

Fair

Over: DRAINAGE

098401001, Osceola, IA

Built 1900 Load: 20.1 t ADT: 758

FM

Fair

Over: DRAINAGE

098401502, Osceola, IA

Built 1954 Load: 20.1 t ADT: 100

LOCAL

Fair

Over: STREAM

098412601, Osceola, IA

Built 1967 Load: 20.1 t ADT: 26

Showing 2,601-2,650 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.