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: LOST CREEK

068031905, Lee, IA

Built 1970 Load: 17.0 t ADT: 450

FM

Fair

Over: BR OF LITTLE WHITEBREAST

072220106, Lucas, IA

Built 1950 Load: 17.0 t ADT: 60

FM

Fair

Over: ENGLISH CREEK

073212503, Lucas, IA

Built 1970 Load: 17.0 t ADT: 90

US 75

Fair

Over: DRAINAGE DITCH

3.8 mi. N of N Jct. IA 9, Lyon, IA

Built 1935 Load: 17.0 t ADT: 1,500

FM K-18

Fair

Over: BROKEN KETTLE CREEK

091482706, Plymouth, IA

Built 1979 Load: 17.0 t ADT: 490

FM

Fair

Over: MINK CREEK

093462202, Plymouth, IA

Built 1961 Load: 17.0 t ADT: 559

630TH AVE

Fair

Over: CALAMUS CREEK

082222002, Story, IA

Built 1972 Load: 17.0 t ADT: 15

FM

Fair

Over: SMALL STREAM

068340101, Taylor, IA

Built 1945 Load: 17.0 t ADT: 71

LOCAL ROAD

Fair

Over: CANOE CREEK

099081503, Winneshiek, IA

Built 1900 Load: 17.0 t ADT: 11

LOCAL

Fair

Over: CREEK

078363202, Audubon, IA

Built 1973 Load: 17.1 t ADT: 62

US 20

Fair

Over: DRAINAGE

1.9 mi. E of E Jct. I-380, Black Hawk, IA

Built 1980 Load: 17.1 t ADT: 10,200

PIEDMONT AVE

Fair

Over: CRANE CREEK

091123402, Bremer, IA

Built 1951 Load: 17.1 t ADT: 44

VAIL AVE

Fair

Over: SMALL STREAM

093152202, Butler, IA

Built 1953 Load: 17.1 t ADT: 34

FM - 710TH

Fair

Over: WATERWAY

075350102, Cass, IA

Built 1900 Load: 17.1 t ADT: 15

LOCAL

Fair

Over: BALDWIN CREEK

081041506, Cedar, IA

Built 1958 Load: 17.1 t ADT: 34

130TH

Fair

Over: BEAVER DAM CREEK

094202001, Cerro Gordo, IA

Built 1959 Load: 17.1 t ADT: 49

FIR

Fair

Over: WILLOW CREEK

096220104, Cerro Gordo, IA

Built 1918 Load: 17.1 t ADT: 82

LOCAL-K AVE.

Fair

Over: SMALL CREEK

092413502, Cherokee, IA

Built 1926 Load: 17.1 t ADT: 11

FM

Fair

Over: WHITE BREAST CREEK

071240304, Clarke, IA

Built 1958 Load: 17.1 t ADT: 50

FM

Fair

Over: CLARK CREEK

082411304, Crawford, IA

Built 1958 Load: 17.1 t ADT: 71

LOCAL

Fair

Over: WALNUT CREEK

083381701, Crawford, IA

Built 1958 Load: 17.1 t ADT: 82

FM

Fair

Over: WALNUT CREEK

083382003, Crawford, IA

Built 1958 Load: 17.1 t ADT: 34

LOCAL

Fair

Over: SMALL STREAM

085410301, Crawford, IA

Built 1958 Load: 17.1 t ADT: 26

FM

Fair

Over: BELL BRANCH

070141203, Davis, IA

Built 1957 Load: 17.1 t ADT: 120

LOCAL

Fair

Over: KILGORE

067251204, Decatur, IA

Built 2001 Load: 17.1 t ADT: 41

FM

Fair

Over: LITTLE RIVER

068253303, Decatur, IA

Built 1957 Load: 17.1 t ADT: 40

LOCAL

Fair

Over: TRIB TO GRAND RIVER

069270203, Decatur, IA

Built 1969 Load: 17.1 t ADT: 26

LOCAL

Fair

Over: DOLBEE CREEK

072023304, Des Moines, IA

Built 1984 Load: 17.1 t ADT: 73

MALLARD AVE

Fair

Over: SPRING CR

092201902, Franklin, IA

Built 1961 Load: 17.1 t ADT: 47

220TH STREET

Fair

Over: DRAINAGE DITCH NO 55

093212501, Franklin, IA

Built 1959 Load: 17.1 t ADT: 16

390 AVE

Fair

Over: MILL CREEK

067400402, Fremont, IA

Built 1959 Load: 17.1 t ADT: 50

220 STREET

Fair

Over: POSSUM CREEK

068430803, Fremont, IA

Built 1957 Load: 17.1 t ADT: 210

380 AVENUE

Fair

Over: WALNUT CREEK

069400404, Fremont, IA

Built 1961 Load: 17.1 t ADT: 11

150 STREET

Fair

Over: HUNTER BRANCH

070403203, Fremont, IA

Built 1961 Load: 17.1 t ADT: 40

150 STREET

Fair

Over: PLUM CREEK

070423103, Fremont, IA

Built 1962 Load: 17.1 t ADT: 41

150 TH

Fair

Over: CEDAR CREEK

085323303, Greene, IA

Built 1949 Load: 17.1 t ADT: 62

FM

Fair

Over: BEAVER CREEK

078310108, Guthrie, IA

Built 1959 Load: 17.1 t ADT: 34

LOCAL

Fair

Over: SEELY CREEK

079320704, Guthrie, IA

Built 1959 Load: 17.1 t ADT: 29

LOCAL

Fair

Over: SKUNK RIVER

088233001, Hamilton, IA

Built 1949 Load: 17.1 t ADT: 15

1780 HILL AVE

Fair

Over: TRIB BOONE RIVER #8

095252902, Hancock, IA

Built 1957 Load: 17.1 t ADT: 15

170TH LANE

Fair

Over: ALLEN CREEK

080430507, Harrison, IA

Built 1969 Load: 17.1 t ADT: 11

HILLSIDE AVE

Fair

Over: STEER CREEK

080441106, Harrison, IA

Built 1963 Load: 17.1 t ADT: 40

135TH ST

Fair

Over: CRANE CREEK

098131003, Howard, IA

Built 1951 Load: 17.1 t ADT: 20

LOCAL

Fair

Over: SILVER CREEK

088391502, Ida, IA

Built 1957 Load: 17.1 t ADT: 15

S 76TH AVE E

Fair

Over: ELK CREEK

078180403, Jasper, IA

Built 1950 Load: 17.1 t ADT: 35

FM

Fair

Over: PICAYUNE CR

078072906, Johnson, IA

Built 1976 Load: 17.1 t ADT: 240

NE 340TH ST

Fair

Over: STREAM

079050201, Johnson, IA

Built 1952 Load: 17.1 t ADT: 51

FM 310TH ST

Fair

Over: STREAM

080052503, Johnson, IA

Built 1900 Load: 17.1 t ADT: 60

TAFT AVE

Fair

Over: STREAM

081051804, Johnson, IA

Built 1970 Load: 17.1 t ADT: 31

FM JOHNS-IOWA R

Fair

Over: STREAM

081080602, Johnson, IA

Built 1966 Load: 17.1 t ADT: 730

Showing 1,801-1,850 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.