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

LOCAL- 600TH ST

Good

Over: WILLOW CREEK

090410601, Cherokee, IA

Built 1997 Load: 37.8 t ADT: 11

LOCAL

Good

Over: STREAM

086401703, Ida, IA

Built 2001 Load: 37.8 t ADT: 11

BIG SPRINGS RD

Good

Over: TRIB TO INDIAN CREEK

084062100, Linn, IA

Built 2003 Load: 37.8 t ADT: 20

250TH ST

Good

Over: LITTLE OCHEYDAN

098393005, Osceola, IA

Built 2006 Load: 37.8 t ADT: 279

145TH RD

Good

Over: STREAM

073342906, Adams, IA

Built 2015 Load: 37.9 t ADT: 15

BRADY DR

Good

Over: BR PAINT CREEK

097042703, Allamakee, IA

Built 2012 Load: 37.9 t ADT: 60

LOCAL

Good

Over: TROUBLESOME CREEK

078352403, Audubon, IA

Built 1994 Load: 37.9 t ADT: 26

INDIAN CREEK RD

Good

Over: SPRING CREEK

88-11-13-01-10, Black Hawk, IA

Built 2011 Load: 37.9 t ADT: 59

WESTBROOK RD

Good

Over: TRIB TO BEAVER CREEK

89-14-05-03-10, Black Hawk, IA

Built 2004 Load: 37.9 t ADT: 97

C33

Good

Over: DRY RUN CREEK

092151607, Butler, IA

Built 2004 Load: 37.9 t ADT: 1,002

T47 PEARL AVE

Good

Over: ALRY CREEK

092161506, Butler, IA

Built 2019 Load: 37.9 t ADT: 49

LOCAL

Good

Over: SMALL STREAM

090163604, Butler, IA

Built 1994 Load: 37.9 t ADT: 51

DELTA AVE

Good

Over: WEST NISHNABOTNA RIVER

082360302, Carroll, IA

Built 2011 Load: 37.9 t ADT: 847

FM

Good

Over: BRUSHY FORK CREEK

083351705, Carroll, IA

Built 2008 Load: 37.9 t ADT: 477

FRANKLIN AVE

Good

Over: M BR WAPSIPINONOC CREEK

079043602, Cedar, IA

Built 2010 Load: 37.9 t ADT: 60

250TH ST

Good

Over: SUGAR CREEK

080012001, Cedar, IA

Built 2018 Load: 37.9 t ADT: 34

273RD ST

Good

Over: ROCK CREEK

080033603, Cedar, IA

Built 1978 Load: 37.9 t ADT: 60

N18 340TH AVE

Good

Over: LOST ISLAND LAKE

096350105, Clay, IA

Built 2021 Load: 37.9 t ADT: 838

150TH ST

Good

Over: ROBERTS CREEK

0.6 m E Concord Ave, Clayton, IA

Built 2016 Load: 37.9 t ADT: 26

205TH ST

Good

Over: ROBERTS CREEK

094052503, Clayton, IA

Built 1991 Load: 37.9 t ADT: 304

370TH ST

Good

Over: ELK CREEK

082372202, Crawford, IA

Built 2016 Load: 37.9 t ADT: 82

FM

Good

Over: BRANCH DUGOUT CREEK

100383601, Dickinson, IA

Built 2003 Load: 37.9 t ADT: 100

PAPE RD

Good

Over: HEWITT CREEK

089022203, Dubuque, IA

Built 2017 Load: 37.9 t ADT: 97

BOY SCOUT RD

Good

Over: MID. FK LITTLE MAQUOKETA

090E13503, Dubuque, IA

Built 2006 Load: 37.9 t ADT: 120

S AVE

Good

Over: VOLGA RIVER

093091902, Fayette, IA

Built 2016 Load: 37.9 t ADT: 49

W14 R AVE

Good

Over: VOLGA RIVER

093092902, Fayette, IA

Built 2021 Load: 37.9 t ADT: 501

FM

Good

Over: BEEMIS CREEK

094180302, Floyd, IA

Built 2010 Load: 37.9 t ADT: 206

D 25

Good

Over: CREEK

088220401, Hardin, IA

Built 2014 Load: 37.9 t ADT: 177

LOCAL

Good

Over: MIDDLE FORK ENGLISH RVR

078112502, Iowa, IA

Built 2004 Load: 37.9 t ADT: 140

125TH STREET

Good

Over: SMALL STREAM

081121411, Iowa, IA

Built 2022 Load: 37.9 t ADT: 60

140TH ST

Good

Over: HONEY CREEK

081122203, Iowa, IA

Built 2018 Load: 37.9 t ADT: 50

IA 64

Good

Over: DRAINAGE DITCH

2.8 MI. E OF U.S. 151, Jones, IA

Built 1979 Load: 37.9 t ADT: 2,760

158TH ST.

Good

Over: HELMER CREEK

085042003, Jones, IA

Built 1988 Load: 37.9 t ADT: 49

COUNTY RD X-31

Good

Over: SILVER CREEK

086041602, Jones, IA

Built 2010 Load: 37.9 t ADT: 383

FM 220TH AVE

Good

Over: NORTH BUFFALO CREEK

098272702, Kossuth, IA

Built 2009 Load: 37.9 t ADT: 339

FM 220TH AVE

Good

Over: NORTH BUFFALO CREEK

098273402, Kossuth, IA

Built 2010 Load: 37.9 t ADT: 339

FM 220TH AVE

Good

Over: NORTH BUFFALO CREEK

098273402, Kossuth, IA

Built 2009 Load: 37.9 t ADT: 339

FM 500TH ST

Good

Over: W BR BLUE EARTH RIVER

100281601, Kossuth, IA

Built 2009 Load: 37.9 t ADT: 150

330TH AVE

Good

Over: DD 84

097300903, Kossuth, IA

Built 2010 Load: 37.9 t ADT: 71

BIRCH AVE

Good

Over: KLONDIKE CREEK

099481402, Lyon, IA

Built 2021 Load: 37.9 t ADT: 103

FM

Good

Over: BLUFF CREEK

074162002, Mahaska, IA

Built 1991 Load: 37.9 t ADT: 100

FM

Good

Over: OVER NS RR

074181301, Marion, IA

Built 2008 Load: 37.9 t ADT: 90

320TH ST

Good

Over: CLEAR CREEK

082202903, Marshall, IA

Built 2017 Load: 37.9 t ADT: 69

E67 (330TH ST)

Good

Over: NORTH SKUNK RIVER

082203601, Marshall, IA

Built 2014 Load: 37.9 t ADT: 20

260TH ST

Good

Over: NORTH TIMBER CREEK

083182402, Marshall, IA

Built 2021 Load: 37.9 t ADT: 176

FA-JAMISON ROAD

Good

Over: INDIAN CREEK

072402409, Mills, IA

Built 1994 Load: 37.9 t ADT: 428

N18 T AVE

Good

Over: W NODAWAY RIVER

072363302, Montgomery, IA

Built 2015 Load: 37.9 t ADT: 29

WARBLER AVE

Good

Over: LITTLE WATERMAN CR

096393302, O'Brien, IA

Built 2019 Load: 37.9 t ADT: 35

IA 60 SB

Good

Over: DME RR

0.6 mi S of jct US 18, O'Brien, IA

Built 2005 Load: 37.9 t ADT: 2,600

IA 60 NB

Good

Over: DME RR

0.6 mi. S of jct. US 18, O'Brien, IA

Built 2005 Load: 37.9 t ADT: 2,600

Showing 13,601-13,650 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.