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-F AVE.

Structurally Deficient

Over: W FORK LITTLE SIOUX RVR

092422402, Cherokee, IA

Built 1924 Load: 8.8 t ADT: 26

FM

Structurally Deficient

Over: ELK CREEK

069271704, Decatur, IA

Built 1983 Load: 8.8 t ADT: 26

320TH ST

Structurally Deficient

Over: BIG WHISKEY CREEK

090453001, Plymouth, IA

Built 1900 Load: 8.8 t ADT: 11

LOCAL

Structurally Deficient

Over: SMALL STREAM

071292702, Union, IA

Built 1900 Load: 8.8 t ADT: 5

FM

Structurally Deficient

Over: CREEK

100071305, Winneshiek, IA

Built 1915 Load: 8.8 t ADT: 59

LOCAL

Structurally Deficient

Over: BR RACCOON RIVER

090360202, Buena Vista, IA

Built 1972 Load: 8.9 t ADT: 15

LOCAL

Structurally Deficient

Over: CHARITON CREEK

071242208, Clarke, IA

Built 1900 Load: 8.9 t ADT: 34

1290 ECHO AVE

Structurally Deficient

Over: BOONE RIVER

094262302, Hancock, IA

Built 1969 Load: 8.9 t ADT: 20

LOCAL

Structurally Deficient

Over: STREAM

067300801, Ringgold, IA

Built 1947 Load: 8.9 t ADT: 34

LOCAL

Structurally Deficient

Over: GOOSEBERRY CREEK

068290201, Ringgold, IA

Built 1965 Load: 8.9 t ADT: 20

LOCAL

Structurally Deficient

Over: SMALL STREAM

082132104, Tama, IA

Built 1986 Load: 8.9 t ADT: 29

LOCAL

Structurally Deficient

Over: CREEK

070320602, Taylor, IA

Built 1953 Load: 8.9 t ADT: 5

235TH STREET

Structurally Deficient

Over: KEMP CREEK

071351203, Adams, IA

Built 1940 Load: 9.0 t ADT: 26

LOCAL

Structurally Deficient

Over: SMALL STREAM

068353002, Taylor, IA

Built 1974 Load: 9.0 t ADT: 11

LOCAL

Structurally Deficient

Over: WHEELER CREEK

091231501, Wright, IA

Built 1978 Load: 9.0 t ADT: 51

190TH ST

Structurally Deficient

Over: STREAM

084282102, Boone, IA

Built 1900 Load: 9.1 t ADT: 20

510TH ST

Structurally Deficient

Over: WEST FORK LITTLE SIOUX

092422401, Cherokee, IA

Built 1917 Load: 9.1 t ADT: 5

LCL MRT.ACC.RD

Structurally Deficient

Over: STREAM

093391604, Cherokee, IA

Built 1917 Load: 9.1 t ADT: 11

LOCAL

Structurally Deficient

Over: SMALL STREAM

072273304, Clarke, IA

Built 1900 Load: 9.1 t ADT: 20

LOCAL

Structurally Deficient

Over: CREEK

084E52805, Jackson, IA

Built 1920 Load: 9.1 t ADT: 79

LOCAL

Structurally Deficient

Over: CREEK

085E53610, Jackson, IA

Built 1930 Load: 9.1 t ADT: 40

FM SW COSGRV RD

Structurally Deficient

Over: N BR OLD MAN'S CREEK

079082502, Johnson, IA

Built 1960 Load: 9.1 t ADT: 620

DINGLEBERRY RD

Structurally Deficient

Over: RAPID CR

080052005, Johnson, IA

Built 1960 Load: 9.1 t ADT: 398

LOCAL

Structurally Deficient

Over: WOLF CREEK

071222510, Lucas, IA

Built 1967 Load: 9.1 t ADT: 26

LOCAL RD

Structurally Deficient

Over: CEDAR CREEK

076282802, Madison, IA

Built 1966 Load: 9.1 t ADT: 26

FM

Structurally Deficient

Over: STREAM

073160306, Monroe, IA

Built 1958 Load: 9.1 t ADT: 25

T AVENUE

Structurally Deficient

Over: STREAM

069361604, Page, IA

Built 1976 Load: 9.1 t ADT: 50

LOCAL

Structurally Deficient

Over: STREAM

096331802, Palo Alto, IA

Built 1955 Load: 9.1 t ADT: 60

LOCAL

Structurally Deficient

Over: STREAM

070312302, Ringgold, IA

Built 1948 Load: 9.1 t ADT: 40

LOCAL

Structurally Deficient

Over: BR SUGAR CREEK

084160602, Tama, IA

Built 1920 Load: 9.1 t ADT: 29

LOCAL

Structurally Deficient

Over: HONEY CREEK

069323302, Taylor, IA

Built 1958 Load: 9.1 t ADT: 15

135TH AVE

Structurally Deficient

Over: TWISTER BRANCH

089242901, Winnebago, IA

Built 1999 Load: 9.1 t ADT: 11

LOCAL

Structurally Deficient

Over: CREEK

092232602, Wright, IA

Built 1900 Load: 9.1 t ADT: 47

E 64TH ST S

Structurally Deficient

Over: STREAM

078181806, Jasper, IA

Built 1940 Load: 9.2 t ADT: 5

LOCAL

Structurally Deficient

Over: EAST BIG CREEK

068283601, Ringgold, IA

Built 1951 Load: 9.2 t ADT: 26

FM 260TH ST

Structurally Deficient

Over: CRAIN CREEK

091122801, Bremer, IA

Built 1965 Load: 9.3 t ADT: 776

LOCAL

Structurally Deficient

Over: LOCAL CREEK

073260903, Clarke, IA

Built 1968 Load: 9.3 t ADT: 71

FM

Structurally Deficient

Over: FROST CREEK

080332302, Guthrie, IA

Built 1959 Load: 9.3 t ADT: 20

LOCAL

Structurally Deficient

Over: MILLER CREEK

078092402, Iowa, IA

Built 1930 Load: 9.3 t ADT: 30

LOCAL

Structurally Deficient

Over: SMALL STREAM

089351301, Sac, IA

Built 1924 Load: 9.3 t ADT: 11

LOCAL

Structurally Deficient

Over: SAND CREEK

071281904, Union, IA

Built 1967 Load: 9.3 t ADT: 41

B60-IVORY RD

Structurally Deficient

Over: NORTH CEDAR CREEK

094031704, Clayton, IA

Built 1913 Load: 9.4 t ADT: 5

LOCAL

Structurally Deficient

Over: STREAM

072292504, Union, IA

Built 1988 Load: 9.4 t ADT: 46

LOCAL

Structurally Deficient

Over: WOLF CREEK

087441603, Woodbury, IA

Built 1938 Load: 9.4 t ADT: 11

LOCAL

Structurally Deficient

Over: LUICKS CREEK

092230401, Wright, IA

Built 1979 Load: 9.4 t ADT: 51

LOCAL

Structurally Deficient

Over: WOLF CREEK

070260207, Decatur, IA

Built 1964 Load: 9.5 t ADT: 11

LOCAL

Structurally Deficient

Over: SMALL STREAM

073282101, Union, IA

Built 1900 Load: 9.5 t ADT: 30

FM

Structurally Deficient

Over: SMALL STREAM

092181201, Butler, IA

Built 1953 Load: 9.6 t ADT: 35

LOCAL/KEYSTONE

Structurally Deficient

Over: SPRING CREEK

076372701, Cass, IA

Built 1900 Load: 9.6 t ADT: 15

LOCAL

Structurally Deficient

Over: LONG CREEK

070262803, Decatur, IA

Built 1915 Load: 9.6 t ADT: 15

Showing 20,101-20,150 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.