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 S TIMBER CREEK

083172004, Marshall, IA

Built 1938 Load: 42.4 t ADT: 11

FM

Poor

Over: DRY CREEK

083091102, Benton, IA

Built 1961 Load: 42.6 t ADT: 1,444

255TH AVE

Poor

Over: CREEK

081E33404, Clinton, IA

Built 1988 Load: 42.9 t ADT: 11

LOCAL

Poor

Over: LITTLE RIVER

070253101, Decatur, IA

Built 1960 Load: 43.3 t ADT: 21

FM

Poor

Over: LITTLE BEAR CREEK

080152002, Poweshiek, IA

Built 1977 Load: 43.4 t ADT: 770

FM

Poor

Over: DOWD CREEK

087183301, Grundy, IA

Built 1964 Load: 43.5 t ADT: 98

HESS RD

Poor

Over: TRIB TO MILLER CREEK

87-13-12-02-20, Black Hawk, IA

Built 1960 Load: 44.2 t ADT: 29

FM

Poor

Over: STEPHENS CREEK

090481506, Plymouth, IA

Built 1960 Load: 44.3 t ADT: 628

242ND TRAIL

Poor

Over: DRAINAGE DITCH

079431605, Harrison, IA

Built 2013 Load: 44.5 t ADT: 34

LOCAL

Poor

Over: CREEK

085E50503, Jackson, IA

Built 1969 Load: 44.7 t ADT: 20

LOCAL

Poor

Over: BROWN CREEK

099341306, Emmet, IA

Built 1941 Load: 45.0 t ADT: 110

LOCAL

Poor

Over: SMALL CREEK

096140301, Chickasaw, IA

Built 1986 Load: 45.2 t ADT: 35

FM

Poor

Over: PRAIRE CREEK

088283504, Webster, IA

Built 1996 Load: 45.3 t ADT: 319

LOCAL

Poor

Over: CREEK

085190303, Marshall, IA

Built 1983 Load: 45.4 t ADT: 11

SOLDIER CR DR

Poor

Over: SOLDIER CREEK

089280900, Webster, IA

Built 1999 Load: 45.4 t ADT: 790

LOCAL

Poor

Over: DRY CREEK

083091202, Benton, IA

Built 1976 Load: 45.5 t ADT: 39

LOCAL

Poor

Over: MUNNS CREEK

087163003, Grundy, IA

Built 1957 Load: 46.7 t ADT: 20

FM

Poor

Over: CREEK

087451002, Woodbury, IA

Built 1955 Load: 46.9 t ADT: 549

LOCAL

Poor

Over: BRANCH BRADLEY CREEK

079091303, Iowa, IA

Built 1965 Load: 47.0 t ADT: 26

FM

Poor

Over: STREAM

074050301, Louisa, IA

Built 1977 Load: 47.2 t ADT: 260

FM

Poor

Over: SMALL

088E13203, Dubuque, IA

Built 1996 Load: 48.2 t ADT: 540

LOC 170TH ST

Poor

Over: SMALL STREAM

072310901, Union, IA

Built 1988 Load: 48.2 t ADT: 113

LANTERN AVE

Poor

Over: MINERS CREEK

092031203, Clayton, IA

Built 1912 Load: 49.2 t ADT: 11

LOCAL

Poor

Over: CREEK

100082904, Winneshiek, IA

Built 1980 Load: 49.2 t ADT: 20

FM

Poor

Over: WALNUT CREEK

081141306, Poweshiek, IA

Built 1990 Load: 49.7 t ADT: 650

LOCAL

Poor

Over: BEAVER CREEK

079313405, Guthrie, IA

Built 2004 Load: 49.8 t ADT: 60

LOCAL

Poor

Over: STEIN CK

084121704, Benton, IA

Built 1999 Load: 51.2 t ADT: 11

E 132ND ST S

Poor

Over: SMALL STREAM

079172204, Jasper, IA

Built 1952 Load: 51.9 t ADT: 30

WORCHESTER RD

Poor

Over: MORGAN CREEK

083082205, Linn, IA

Built 2000 Load: 52.4 t ADT: 439

LOCAL

Poor

Over: NORTH SKUNK RIVER

081190902, Jasper, IA

Built 1988 Load: 52.6 t ADT: 50

FM

Poor

Over: DD 181 BIG CEDAR

089342101, Calhoun, IA

Built 1938 Load: 52.9 t ADT: 219

FM 280TH AVE

Poor

Over: PICKERAL RUN

096351902, Clay, IA

Built 1993 Load: 52.9 t ADT: 459

LOCAL

Poor

Over: IOWA RIVER (SOUTH FORK)

087200702, Hardin, IA

Built 1997 Load: 52.9 t ADT: 62

FM

Poor

Over: MUD CREEK

078E11002, Muscatine, IA

Built 1948 Load: 54.1 t ADT: 290

255TH ST

Poor

Over: LITTLE INDIAN CREEK

088361903, Sac, IA

Built 1968 Load: 58.4 t ADT: 928

FM

Poor

Over: WOLF CREEK, BRANCH

086170704, Grundy, IA

Built 1972 Load: 60.4 t ADT: 373

FM

Poor

Over: SO BRANCH SALT CREEK

084151203, Tama, IA

Built 1996 Load: 60.6 t ADT: 344

FM

Poor

Over: PRAIRIE CREEK

082112101, Benton, IA

Built 1960 Load: 62.9 t ADT: 820

300TH AVE

Poor

Over: AMES CREEK

081E40402, Clinton, IA

Built 1912 Load: 65.3 t ADT: 16

FM

Poor

Over: CREEK

069142804, Davis, IA

Built 1973 Load: 70.4 t ADT: 1,260

FM

Poor

Over: CREEK

072282306, Union, IA

Built 1964 Load: 70.9 t ADT: 409

FM

Poor

Over: SMALL NATURAL STREAM

070273418, Decatur, IA

Built 1939 Load: 73.3 t ADT: 278

LOCAL

Poor

Over: SCHOOL CREEK

0993416, Emmet, IA

Built 1933 Load: 84.1 t ADT: 50

S23 200TH AVE

Poor

Over: STONY FORK

073221104, Lucas, IA

Built 1969 Load: 88.3 t ADT: 400

FM

Poor

Over: BRANCH BEE CREEK

071261604, Clarke, IA

Built 1985 Load: 89.7 t ADT: 131

G76

Poor

Over: SMALL STREAM

074211503, Marion, IA

Built 1964 Load: 89.8 t ADT: 500

FM

Poor

Over: WOLF CREEK, BRANCH

086173201, Grundy, IA

Built 1975 Load: 99.9 t ADT: 1,394

LOCAL

Poor

Over: BREWERS CREEK

089263501, Hamilton, IA

Built 1971 Load: 99.9 t ADT: 34

FM

Poor

Over: JONES CREEK

075273102, Madison, IA

Built 1929 Load: 99.9 t ADT: 788

FM

Poor

Over: HAWKRUN CREEK

075200802, Marion, IA

Built 1967 Load: 99.9 t ADT: 70

Showing 19,301-19,350 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.