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

Good

Over: STREAM

076112903, Keokuk, IA

Built 2007 Load: 26.5 t ADT: 30

LOCAL

Good

Over: BRANCH BUCKEYE CREEK

072122903, Wapello, IA

Built 1999 Load: 26.5 t ADT: 21

V43

Good

Over: WATERWAY

091121502, Bremer, IA

Built 2006 Load: 26.6 t ADT: 69

LOC 150TH ST

Good

Over: SMALL CREEK

090073601, Buchanan, IA

Built 2004 Load: 26.6 t ADT: 34

170TH AVE.

Good

Over: DRAINAGE DITCH 12

082E20802, Clinton, IA

Built 1962 Load: 26.6 t ADT: 35

160TH AVE

Good

Over: DRAINAGE DITCH #12

082E23002, Clinton, IA

Built 1980 Load: 26.6 t ADT: 41

150TH ST.

Good

Over: DRAINAGE

083E13403, Clinton, IA

Built 1970 Load: 26.6 t ADT: 21

110TH ST.

Good

Over: PRAIRIE CREEK

083E20805, Clinton, IA

Built 1965 Load: 26.6 t ADT: 90

432ND AVENUE

Good

Over: SPRING CREEK

083E62704, Clinton, IA

Built 1969 Load: 26.6 t ADT: 780

150TH ST.

Good

Over: SPRING CREEK

083E63403, Clinton, IA

Built 1976 Load: 26.6 t ADT: 15

X 99

Good

Over: DOLBEE CREEK

072022406, Des Moines, IA

Built 1938 Load: 26.6 t ADT: 900

340TH ST

Good

Over: CREEK

0.3 Mi E Valley Ave, Mitchell, IA

Built 2017 Load: 26.6 t ADT: 49

A43 390TH ST

Good

Over: SOAP CREEK

0.4 Mi W Valley Ave, Mitchell, IA

Built 2017 Load: 26.6 t ADT: 20

380TH

Good

Over: SOAP CREEK

098151701, Mitchell, IA

Built 2004 Load: 26.6 t ADT: 29

370TH

Good

Over: SUGAR CREEK

098172305, Mitchell, IA

Built 2004 Load: 26.6 t ADT: 333

440TH

Good

Over: BEAVER CREEK

0.25 Mi W of Timber Ave, Mitchell, IA

Built 2016 Load: 26.6 t ADT: 11

TIMBER AVE

Good

Over: BEAVER CREEK

.2 m N of 430th, Mitchell, IA

Built 2012 Load: 26.6 t ADT: 39

450TH ST

Good

Over: CREEK

450th 0.15 mW of Primrose, Mitchell, IA

Built 2013 Load: 26.6 t ADT: 49

465TH

Good

Over: WAPSIPINICON RIVER

100153303, Mitchell, IA

Built 2010 Load: 26.6 t ADT: 20

WINDFALL AVE

Good

Over: CREEK

.05 m N of 460th St, Mitchell, IA

Built 2012 Load: 26.6 t ADT: 15

OCEAN AVE

Good

Over: LITTLE CEDAR RIVER

100161606, Mitchell, IA

Built 2003 Load: 26.6 t ADT: 21

DANCER AVE

Good

Over: OTTER CREEK

000000000, Mitchell, IA

Built 2009 Load: 26.6 t ADT: 33

MARCH AVE

Good

Over: CREEK

.3 m S of 480th, Mitchell, IA

Built 2013 Load: 26.6 t ADT: 26

LOCAL RD

Good

Over: NELSON CREEK

094401702, O'Brien, IA

Built 1990 Load: 26.6 t ADT: 50

FM

Good

Over: LANGE CR

094411702, O'Brien, IA

Built 1967 Load: 26.6 t ADT: 45

POLK AVE

Good

Over: SO BR LITTLE FLOYD RIVER

096410902, O'Brien, IA

Built 2015 Load: 26.6 t ADT: 30

IA 60

Good

Over: DRAINAGE DITCH

0.4 mi. S of jct. SR C16, Plymouth, IA

Built 2003 Load: 26.6 t ADT: 6,900

400TH

Good

Over: DRAINAGE DITCH

098220401, Worth, IA

Built 1915 Load: 26.6 t ADT: 26

YARROW AVE

Good

Over: STREAM

0.8 Mi N A17, Worth, IA

Built 2017 Load: 26.6 t ADT: 5

JUNIPER AVE

Good

Over: STREAM

100213402, Worth, IA

Built 2003 Load: 26.6 t ADT: 20

JONQUIL AVE

Good

Over: DRAINAGE DITCH

100213404, Worth, IA

Built 2013 Load: 26.6 t ADT: 41

LAFAYETTE ST

Good

Over: BLOWERS CREEK

CITY BRIDGE NO. 19, Black Hawk, IA

Built 1991 Load: 26.7 t ADT: 5,195

180TH ST

Good

Over: BUCK CREEK

092111601, Bremer, IA

Built 1998 Load: 26.7 t ADT: 49

J 52 280TH ST

Good

Over: DICKENSON BRANCH

067260403, Decatur, IA

Built 2018 Load: 26.7 t ADT: 103

IA 3

Good

Over: BIG WHISKEY SLOUGH

0.6 mi W of jct SR L22, Plymouth, IA

Built 1999 Load: 26.7 t ADT: 2,140

35TH AVENUE

Good

Over: BNRR

35th Ave over BNSF, Pottawattamie, IA

Built 1994 Load: 26.7 t ADT: 5,316

LOCAL

Good

Over: STREAM

076311803, Adair, IA

Built 2003 Load: 26.8 t ADT: 51

LOCAL

Good

Over: STREAM

076331601, Adair, IA

Built 2002 Load: 26.8 t ADT: 41

150TH ST

Good

Over: STREAM

077333101, Adair, IA

Built 2005 Load: 26.8 t ADT: 15

150TH ST

Good

Over: BRANCH OF NODAWAY RIVER

077333601, Adair, IA

Built 2005 Load: 26.8 t ADT: 21

LOCAL

Good

Over: BRANCH, NODAWAY RIVER

077333602, Adair, IA

Built 2002 Load: 26.8 t ADT: 26

E WASHBURN RD

Good

Over: TRIB TO MILLER CREEK

88-13-25-01-10, Black Hawk, IA

Built 1977 Load: 26.8 t ADT: 462

170TH ST

Good

Over: BUCK CREEK

092110901, Bremer, IA

Built 2015 Load: 26.8 t ADT: 29

200TH AVE

Good

Over: PRAIRIE CREEK

096373502, Clay, IA

Built 2003 Load: 26.8 t ADT: 11

MAPLE RD

Good

Over: LITTLE TURKEY RIVER

095091307, Fayette, IA

Built 1986 Load: 26.8 t ADT: 49

160 STREET

Good

Over: WALNUT CREEK

069400401, Fremont, IA

Built 1986 Load: 26.8 t ADT: 21

S BRANCH RD

Good

Over: S BR TURKEY RIVER

099122602, Howard, IA

Built 2021 Load: 26.8 t ADT: 21

LOCAL

Good

Over: CREEK

089392902, Ida, IA

Built 2001 Load: 26.8 t ADT: 26

FM

Good

Over: E FOURMILE CK

079232603, Polk, IA

Built 2005 Load: 26.8 t ADT: 2,560

FM

Good

Over: WEST NISHNABOTNA RIVER

078393203, Shelby, IA

Built 1985 Load: 26.8 t ADT: 100

Showing 9,701-9,750 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.