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: FLOOD CREEK

096181104, Floyd, IA

Built 1969 Load: 26.6 t ADT: 39

NETTLE AVE

Fair

Over: MAYNES CR

091203202, Franklin, IA

Built 1973 Load: 26.6 t ADT: 51

BALSAM AVE

Fair

Over: DRAINAGE DITCH #32

091222902, Franklin, IA

Built 1969 Load: 26.6 t ADT: 44

FM MALLARD AVE

Fair

Over: OTTER CREEK

093201902, Franklin, IA

Built 1963 Load: 26.6 t ADT: 49

FM

Fair

Over: BEAVER CREEK

088200701, Hardin, IA

Built 1942 Load: 26.6 t ADT: 44

FM 150TH ST

Fair

Over: LITTLE WAPSIPINICON

098142203, Howard, IA

Built 1967 Load: 26.6 t ADT: 452

LOCAL

Fair

Over: DD

093282301, Humboldt, IA

Built 1955 Load: 26.6 t ADT: 5

IA 149

Fair

Over: ENGLISH CREEK

0.4 MI. S OF SR F67, Iowa, IA

Built 1987 Load: 26.6 t ADT: 2,010

LOCAL

Fair

Over: SMALL CREEK

084E63304, Jackson, IA

Built 1969 Load: 26.6 t ADT: 79

FM

Fair

Over: TURKEY CREEK

080200509, Jasper, IA

Built 1963 Load: 26.6 t ADT: 300

FM SW NAPLES AV

Fair

Over: PICAYUNE CREEK

078062002, Johnson, IA

Built 1966 Load: 26.6 t ADT: 70

FM SW BLK DIMND

Fair

Over: N BRANCH OLD MAN'S CREEK

079073009, Johnson, IA

Built 1968 Load: 26.6 t ADT: 650

FM SUGAR BTM RD

Fair

Over: TURKEY CREEK

080061105, Johnson, IA

Built 1964 Load: 26.6 t ADT: 990

FM

Fair

Over: PLUM CREEK

081082403, Johnson, IA

Built 1934 Load: 26.6 t ADT: 130

160TH AVE.

Fair

Over: WALNUT CREEK

083032702, Jones, IA

Built 1974 Load: 26.6 t ADT: 49

COUNTY RD. E-45

Fair

Over: NORTH FORK WALNUT CREEK

083041003, Jones, IA

Built 1966 Load: 26.6 t ADT: 570

COUNTY RD E-45

Fair

Over: SMALL CREEK

083041003, Jones, IA

Built 1966 Load: 26.6 t ADT: 570

COVINGTON RD

Fair

Over: DRY CREEK

000000000, Linn, IA

Built 1955 Load: 26.6 t ADT: 3,107

LINN-BENTON RD

Fair

Over: KNAPP CREEK

082083108, Linn, IA

Built 1972 Load: 26.6 t ADT: 730

LUCORE RD

Fair

Over: INDIAN CR

084061914, Linn, IA

Built 1972 Load: 26.6 t ADT: 2,445

CENTRAL CITY RD

Fair

Over: EAST OTTER CREEK

085071101, Linn, IA

Built 1962 Load: 26.6 t ADT: 982

PARIS RD

Fair

Over: RIVER BEND CREEK

086072501, Linn, IA

Built 1963 Load: 26.6 t ADT: 344

ALBURNETT RD

Fair

Over: RIVER BEND CREEK

086072502, Linn, IA

Built 1963 Load: 26.6 t ADT: 462

LOCAL

Fair

Over: SMALL STREAM

073030804, Louisa, IA

Built 1979 Load: 26.6 t ADT: 35

FM

Fair

Over: RAT CREEK

098431301, Lyon, IA

Built 1971 Load: 26.6 t ADT: 399

LOCAL RD

Fair

Over: DRAINAGE

075270103, Madison, IA

Built 1994 Load: 26.6 t ADT: 50

LOCAL

Fair

Over: LITTLE BLUFF CREEK

074163003, Mahaska, IA

Built 1971 Load: 26.6 t ADT: 20

LOCAL

Fair

Over: MOON CREEK

077141907, Mahaska, IA

Built 1961 Load: 26.6 t ADT: 34

LOCAL

Fair

Over: STREAM

073171704, Monroe, IA

Built 1968 Load: 26.6 t ADT: 60

FM

Fair

Over: SWEETLAND CREEK

077012203, Muscatine, IA

Built 1948 Load: 26.6 t ADT: 380

FM

Fair

Over: HOCKEYS SLOUGH

077041404, Muscatine, IA

Built 1977 Load: 26.6 t ADT: 130

LOCAL

Fair

Over: DRAINAGE

078032105, Muscatine, IA

Built 1971 Load: 26.6 t ADT: 41

LOCAL

Fair

Over: WILLOW CR

094412501, O'Brien, IA

Built 1978 Load: 26.6 t ADT: 11

FM

Fair

Over: FLOYD RIVER

097411001, O'Brien, IA

Built 1969 Load: 26.6 t ADT: 45

FM

Fair

Over: LITTLE FLOYD RIVER

097413102, O'Brien, IA

Built 1968 Load: 26.6 t ADT: 409

LOCAL

Fair

Over: DD 61

094310101, Palo Alto, IA

Built 1978 Load: 26.6 t ADT: 82

FM

Fair

Over: DD #41

095332301, Palo Alto, IA

Built 1991 Load: 26.6 t ADT: 518

FM

Fair

Over: CYLINDER CREEK

096310801, Palo Alto, IA

Built 1966 Load: 26.6 t ADT: 193

LOCAL

Fair

Over: LIZARD CREEK

091320801, Pocahontas, IA

Built 1975 Load: 26.6 t ADT: 34

LOCAL

Fair

Over: BIG CEDAR CREEK

092342301, Pocahontas, IA

Built 1974 Load: 26.6 t ADT: 11

LOCAL

Fair

Over: BIG CEDAR CREEK

092342601, Pocahontas, IA

Built 1977 Load: 26.6 t ADT: 11

FM

Fair

Over: E FORK GRAND RIVER

067302503, Ringgold, IA

Built 1961 Load: 26.6 t ADT: 15

LOCAL

Fair

Over: SMALL STREAM

094450802, Sioux, IA

Built 1969 Load: 26.6 t ADT: 40

FM

Fair

Over: ORANGE CITY SLOUGH

094451202, Sioux, IA

Built 1969 Load: 26.6 t ADT: 51

FM

Fair

Over: NO NAME CREEK

094473502, Sioux, IA

Built 1967 Load: 26.6 t ADT: 649

FM

Fair

Over: NO NAME CREEK

096440904, Sioux, IA

Built 1965 Load: 26.6 t ADT: 1,277

FM

Fair

Over: NO NAME CREEK

097433402, Sioux, IA

Built 1968 Load: 26.6 t ADT: 270

FM

Fair

Over: NODAWAY RIVER

073311702, Union, IA

Built 1978 Load: 26.6 t ADT: 29

LOCAL

Fair

Over: BUTTRICK CREEK

086302101, Webster, IA

Built 1970 Load: 26.6 t ADT: 15

160TH ST

Fair

Over: LITTLE WAPSIPINICON RVR

092110201, Bremer, IA

Built 1996 Load: 26.7 t ADT: 39

Showing 4,651-4,700 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.