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: BLUE GRASS CREEK

080351601, Audubon, IA

Built 1962 Load: 26.0 t ADT: 210

JUBILEE RD

Fair

Over: TRIB TO CEDAR RIVER

87-11-06-01-10, Black Hawk, IA

Built 1992 Load: 26.0 t ADT: 79

E GRESHAM RD

Fair

Over: TRIB TO CRANE CREEK

90-12-08-01-10, Black Hawk, IA

Built 1994 Load: 26.0 t ADT: 33

E PARKER ST

Fair

Over: VIRDEN CREEK

CITY CULVERT NO. 37C, Black Hawk, IA

Built 1970 Load: 26.0 t ADT: 606

FM

Fair

Over: MUD CREEK

079010102, Cedar, IA

Built 1986 Load: 26.0 t ADT: 190

FM 130TH AVE

Fair

Over: WILLOW CREEK

095381502, Clay, IA

Built 1964 Load: 26.0 t ADT: 619

LOCAL

Fair

Over: SUGAR CREEK

078261608, Dallas, IA

Built 1978 Load: 26.0 t ADT: 72

COUNTY ROAD

Fair

Over: PANTHER CREEK

079280904, Dallas, IA

Built 1961 Load: 26.0 t ADT: 46

LOCAL

Fair

Over: NORTH WYACONDAH CREEK

068133603, Davis, IA

Built 1958 Load: 26.0 t ADT: 15

LOCAL

Fair

Over: MAYNES CREEK

091202304, Franklin, IA

Built 1952 Load: 26.0 t ADT: 30

342 AVENUE

Fair

Over: DRAINAGE

068412204, Fremont, IA

Built 1960 Load: 26.0 t ADT: 21

FM 1920 260 ST

Fair

Over: EAST IOWA RIVER

096231801, Hancock, IA

Built 1964 Load: 26.0 t ADT: 210

SB I-29

Fair

Over: BURCHAM CREEK

2.8 MI. S OF JCT. 127, Harrison, IA

Built 1967 Load: 26.0 t ADT: 7,600

NB I-29

Fair

Over: DRAINAGE DITCH

1.8 MI. N OF JCT.127, Harrison, IA

Built 1967 Load: 26.0 t ADT: 7,300

SB I-29

Fair

Over: DRAINAGE DITCH

1.8 MI. N OF JCT.127, Harrison, IA

Built 1967 Load: 26.0 t ADT: 7,300

SIOUX AVE

Fair

Over: SMALL STREAM

078181803, Jasper, IA

Built 1928 Load: 26.0 t ADT: 41

LOCAL

Fair

Over: ALLOWAY CREEK

080180905, Jasper, IA

Built 1930 Load: 26.0 t ADT: 30

LOCAL

Fair

Over: SMALL STREAM

075030204, Louisa, IA

Built 1986 Load: 26.0 t ADT: 73

FM

Fair

Over: NORTH CEDAR CREEK

072201803, Lucas, IA

Built 1975 Load: 26.0 t ADT: 150

IA 48

Fair

Over: RED OAK CREEK

1.3 MI S OF JCT. US 34, Montgomery, IA

Built 1918 Load: 26.0 t ADT: 4,460

FM

Fair

Over: LITTLE OCHEYEDAN RIVER

099403201, Osceola, IA

Built 1965 Load: 26.0 t ADT: 71

FM

Fair

Over: PERRY CREEK

091472602, Plymouth, IA

Built 1970 Load: 26.0 t ADT: 1,028

170TH ST

Fair

Over: MINK CREEK

092460903, Plymouth, IA

Built 1934 Load: 26.0 t ADT: 60

LOCAL

Fair

Over: LIZARD CREEK DD#53

091322402, Pocahontas, IA

Built 1957 Load: 26.0 t ADT: 26

LOCAL

Fair

Over: MUD CREEK

079222803, Polk, IA

Built 1936 Load: 26.0 t ADT: 259

FM

Fair

Over: CAMP CREEK

079223602, Polk, IA

Built 1957 Load: 26.0 t ADT: 837

10TH AVE

Fair

Over: CREEK

079E10802, Scott, IA

Built 1960 Load: 26.0 t ADT: 40

LARCH AVE

Fair

Over: CEDAR CREEK

075083604, Washington, IA

Built 1953 Load: 26.0 t ADT: 100

LOCAL ROAD

Fair

Over: DAVIS CREEK

077063104, Washington, IA

Built 1956 Load: 26.0 t ADT: 71

VERMONT AVE

Fair

Over: SMALL

082011502, Cedar, IA

Built 2005 Load: 26.1 t ADT: 60

FM

Fair

Over: HOCKETT CREEK

083371901, Crawford, IA

Built 2006 Load: 26.1 t ADT: 20

LOCAL

Fair

Over: SMALL STREAM

085382803, Crawford, IA

Built 2006 Load: 26.1 t ADT: 15

FM & 170TH ST

Fair

Over: E.PICAYUNE CREEK

080410305, Harrison, IA

Built 1978 Load: 26.1 t ADT: 15

FM

Fair

Over: DD

093293302, Humboldt, IA

Built 1925 Load: 26.1 t ADT: 339

LOG AVE

Fair

Over: WEST RAT CREEK

098431402, Lyon, IA

Built 1900 Load: 26.1 t ADT: 34

LOCAL ROAD

Fair

Over: TAFT CREEK

099432302, Lyon, IA

Built 1900 Load: 26.1 t ADT: 30

LOCAL ROAD

Fair

Over: SMALL STREAM

100431501, Lyon, IA

Built 1900 Load: 26.1 t ADT: 15

LOCAL

Fair

Over: TOM CREEK

077292304, Madison, IA

Built 1987 Load: 26.1 t ADT: 11

LOCAL RD

Fair

Over: WHITE CREEK

072192309, Monroe, IA

Built 1959 Load: 26.1 t ADT: 26

FM

Fair

Over: EAST TARKIO

071373501, Montgomery, IA

Built 1969 Load: 26.1 t ADT: 45

WHIPPERWILL RD

Fair

Over: STREAM

077420901, Pottawattamie, IA

Built 2003 Load: 26.1 t ADT: 30

CO RD Y-68

Fair

Over: CROW CREEK

079E32503, Scott, IA

Built 1954 Load: 26.1 t ADT: 1,680

FM

Fair

Over: BRANCH OF IOWA RIVER

082151203, Tama, IA

Built 1936 Load: 26.1 t ADT: 491

LOCAL

Fair

Over: STREAM

086450301, Woodbury, IA

Built 1999 Load: 26.1 t ADT: 40

CO RD 105

Fair

Over: DRAINAGE DITCH

100203101, Worth, IA

Built 1949 Load: 26.1 t ADT: 1,414

LOCAL

Fair

Over: PAINT CREEK

097051204, Allamakee, IA

Built 1975 Load: 26.2 t ADT: 33

LOCAL

Fair

Over: BR LITTLE ELKHORN CR

079011602, Cedar, IA

Built 1946 Load: 26.2 t ADT: 11

FM-530TH ST.

Fair

Over: WILLOW CREEK

092413101, Cherokee, IA

Built 1968 Load: 26.2 t ADT: 898

LACE AVE

Fair

Over: SM STREAM

093032506, Clayton, IA

Built 1955 Load: 26.2 t ADT: 79

160TH ST

Fair

Over: DEER CREEK

094060102, Clayton, IA

Built 1958 Load: 26.2 t ADT: 51

Showing 4,451-4,500 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.