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

US 218 SB

Good

Over: SOUTH BR OF FISH CREEK

0.7 mi. N of Jct. SR J20, Henry, IA

Built 2003 Load: 38.5 t ADT: 4,850

FM 190TH ST

Good

Over: LITTLE WAPSIPINICON

097141201, Howard, IA

Built 1995 Load: 38.5 t ADT: 638

FM

Good

Over: W FK DES MOINES RIVER

092292904, Humboldt, IA

Built 1990 Load: 38.5 t ADT: 518

FM

Good

Over: BRANCH MIDDLE ENGLISH

078112201, Iowa, IA

Built 2000 Load: 38.5 t ADT: 35

E 132ND ST S

Good

Over: N SKUNK RIVER

079171506, Jasper, IA

Built 1989 Load: 38.5 t ADT: 440

35TH ST

Good

Over: WALNUT CREEK

083032203, Jones, IA

Built 2005 Load: 38.5 t ADT: 44

LCL-CARY AVE

Good

Over: FARM CREEK

073401403, Mills, IA

Built 2007 Load: 38.5 t ADT: 60

480TH ST

Good

Over: LITTLE CEDAR RIVER

100163003, Mitchell, IA

Built 2004 Load: 38.5 t ADT: 44

FM

Good

Over: SOLDIER RIVER

083423006, Monona, IA

Built 2000 Load: 38.5 t ADT: 40

FM

Good

Over: W NODAWAY RIVER

072360901, Montgomery, IA

Built 1999 Load: 38.5 t ADT: 60

LOCAL SEC RD

Good

Over: LANGE CREEK SOUTH

094422402, O'Brien, IA

Built 2001 Load: 38.5 t ADT: 26

FM

Good

Over: OCHEYEDAN RIVER

098392801, Osceola, IA

Built 2004 Load: 38.5 t ADT: 180

FM

Good

Over: JOHN'S CREEK

090442409, Plymouth, IA

Built 1977 Load: 38.5 t ADT: 309

FM-300TH ST

Good

Over: SILVER CREEK

074410602, Pottawattamie, IA

Built 2006 Load: 38.5 t ADT: 1,065

COTTONWOOD ROAD

Good

Over: KEG CREEK

074420301, Pottawattamie, IA

Built 1997 Load: 38.5 t ADT: 50

FM-310TH STREET

Good

Over: KEG CREEK

076410806, Pottawattamie, IA

Built 1973 Load: 38.5 t ADT: 150

FM

Good

Over: PIGEON CREEK

077432404, Pottawattamie, IA

Built 2006 Load: 38.5 t ADT: 528

LOCAL

Good

Over: MOSQUITO CREEK

079403105, Shelby, IA

Built 2000 Load: 38.5 t ADT: 41

SOUTH S AVE

Good

Over: WEST BR INDIAN CREEK

083221901, Story, IA

Built 2004 Load: 38.5 t ADT: 219

IRR FM

Good

Over: RICHLAND CREEK

082161502, Tama, IA

Built 1994 Load: 38.5 t ADT: 471

LOCAL

Good

Over: STREAM

071283605, Union, IA

Built 2005 Load: 38.5 t ADT: 30

LOCAL ROAD

Good

Over: CLANTON CREEK

075250606, Warren, IA

Built 1991 Load: 38.5 t ADT: 72

RACCOON

Good

Over: WALKER CREEK

070203503, Wayne, IA

Built 2015 Load: 38.5 t ADT: 26

LOCAL

Good

Over: TROUT CREEK

098082803, Winneshiek, IA

Built 2003 Load: 38.5 t ADT: 805

LOCAL

Good

Over: MUD CREEK

089452507, Woodbury, IA

Built 1997 Load: 38.5 t ADT: 34

330TH ST

Good

Over: STREAM

0.9 mi W of P13 on 330th, Adair, IA

Built 2021 Load: 38.6 t ADT: 26

493RD ST

Good

Over: STREAM

069172103, Appanoose, IA

Built 2011 Load: 38.6 t ADT: 82

LARK AVE

Good

Over: CREEK

0.25 Mile S. Co Hwy F32, Audubon, IA

Built 2017 Load: 38.6 t ADT: 29

LARK AVE

Good

Over: BR E NISHNABOTNA R

FM 081351202, Audubon, IA

Built 2018 Load: 38.6 t ADT: 50

130TH ST

Good

Over: HORTON CREEK

093142301, Bremer, IA

Built 2020 Load: 38.6 t ADT: 33

LOCAL

Good

Over: SMALL STREAM

093173402, Butler, IA

Built 1998 Load: 38.6 t ADT: 11

IVY AVE.

Good

Over: STREAM

093171602, Butler, IA

Built 1998 Load: 38.6 t ADT: 41

180TH STREET

Good

Over: SMALL STREAM

092171701, Butler, IA

Built 2007 Load: 38.6 t ADT: 26

YARROW

Good

Over: BEAVER CREEK

095192402, Cerro Gordo, IA

Built 1992 Load: 38.6 t ADT: 41

330 TH

Good

Over: ROCK FALLS CREEK

097190901, Cerro Gordo, IA

Built 1971 Load: 38.6 t ADT: 49

US 18

Good

Over: CRANE CREEK

1.9 MI. E OF JCT. I-35, Cerro Gordo, IA

Built 1998 Load: 38.6 t ADT: 8,300

FM 440TH ST

Good

Over: WILLOW CREEK

095373101, Clay, IA

Built 2009 Load: 38.6 t ADT: 399

150TH AVE

Good

Over: STONEY CREEK

097381302, Clay, IA

Built 1994 Load: 38.6 t ADT: 81

HAWK AVE

Good

Over: STREAM

0.6 miles S Hilton Rd, Clayton, IA

Built 2016 Load: 38.6 t ADT: 20

110TH ST.

Good

Over: CREEK

083E30503, Clinton, IA

Built 1995 Load: 38.6 t ADT: 41

FM THUNDER RD

Good

Over: PLUM CREEK

088033303, Delaware, IA

Built 1993 Load: 38.6 t ADT: 34

137TH ST

Good

Over: SMALL STREAM

900422 4580, Delaware, IA

Built 2015 Load: 38.6 t ADT: 44

WORTHINGTON RD

Good

Over: CREEK

088021703, Dubuque, IA

Built 2019 Load: 38.6 t ADT: 69

C AVE

Good

Over: BRANCH BEAVER CREEK

088180502, Grundy, IA

Built 2011 Load: 38.6 t ADT: 26

UTE AVE

Good

Over: STREAM

081300402, Guthrie, IA

Built 2013 Load: 38.6 t ADT: 34

45TH ST

Good

Over: COPPER CREEK

084E52203, Jackson, IA

Built 2020 Load: 38.6 t ADT: 70

S 52ND AVE E

Good

Over: SUGAR CREEK

079172401, Jasper, IA

Built 2012 Load: 38.6 t ADT: 41

E 84TH ST S

Good

Over: ELK CREEK

079183402, Jasper, IA

Built 2019 Load: 38.6 t ADT: 51

TWIN RIVERS RD

Good

Over: OVER BNSF RR

000000000, Lee, IA

Built 1994 Load: 38.6 t ADT: 820

HOGBACK BRIDGE RD

Good

Over: CEDAR CREEK

076282304, Madison, IA

Built 2023 Load: 38.6 t ADT: 150

Showing 13,751-13,800 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.