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

LOC N BRANCH RD

Good

Over: N BR TURKEY RIVER

099121404, Howard, IA

Built 1996 Load: 32.7 t ADT: 26

LILAC AVE

Good

Over: BEAVER CREEK

099130102, Howard, IA

Built 2020 Load: 32.7 t ADT: 29

LOCAL 60TH ST

Good

Over: BEAVER CREEK

099130501, Howard, IA

Built 2003 Load: 32.7 t ADT: 5

LOCAL FIR AVE

Good

Over: BRANCH CRANE CREEK

099141202, Howard, IA

Built 1997 Load: 32.7 t ADT: 62

LOC UNITY AVE

Good

Over: BR NICHOLS CR

100112102, Howard, IA

Built 2005 Load: 32.7 t ADT: 30

30TH ST

Good

Over: NICHOLS CREEK

100112401, Howard, IA

Built 2020 Load: 32.7 t ADT: 62

30TH ST

Good

Over: NICHOLS CREEK

100112401, Howard, IA

Built 2020 Load: 32.7 t ADT: 62

FM

Good

Over: UPPER IOWA

100113303, Howard, IA

Built 2006 Load: 32.7 t ADT: 737

FM-QUAIL AVE

Good

Over: UPPER IOWA

100121404, Howard, IA

Built 1998 Load: 32.7 t ADT: 98

LOCAL

Good

Over: SMALL STREAM

100122105, Howard, IA

Built 1995 Load: 32.7 t ADT: 104

35TH ST

Good

Over: UPPER IOWA RIVER

100122105, Howard, IA

Built 2013 Load: 32.7 t ADT: 104

10TH ST

Good

Over: UNNAMED CREEK

100140903, Howard, IA

Built 1987 Load: 32.7 t ADT: 128

LOCAL RD

Good

Over: SMALL

100110704, Howard, IA

Built 2003 Load: 32.7 t ADT: 5

LOCAL

Good

Over: SMALL

098141603, Howard, IA

Built 2004 Load: 32.7 t ADT: 5

YANKEE AVE

Good

Over: DITCH

100112502, Howard, IA

Built 2013 Load: 32.7 t ADT: 39

25TH ST

Good

Over: DITCH

100991703, Howard, IA

Built 2013 Load: 32.7 t ADT: 35

YOUNG AVE

Good

Over: BR UPPER IOWA

100112504, Howard, IA

Built 2017 Load: 32.7 t ADT: 26

KENT AVE

Good

Over: BRANCH BEAVER CREEK

99130202, Howard, IA

Built 2023 Load: 32.7 t ADT: 10

FM

Good

Over: DM RIVER

093281603, Humboldt, IA

Built 2001 Load: 32.7 t ADT: 478

FM

Good

Over: SOLDIER RIVER

086391501, Ida, IA

Built 1989 Load: 32.7 t ADT: 80

LOCAL

Good

Over: SOLDIER RIVER

086392201, Ida, IA

Built 1994 Load: 32.7 t ADT: 5

FM

Good

Over: SOLDIER RIVER

086392202, Ida, IA

Built 2000 Load: 32.7 t ADT: 11

LOCAL ROAD

Good

Over: SOLDIER RIVER

086392801, Ida, IA

Built 2006 Load: 32.7 t ADT: 11

LOCAL

Good

Over: HOSKINS CREEK

087393501, Ida, IA

Built 2004 Load: 32.7 t ADT: 26

LOCAL

Good

Over: UNAMED CREEK

087402901, Ida, IA

Built 1990 Load: 32.7 t ADT: 35

ALPINE AVE

Good

Over: CREEK

087410802, Ida, IA

Built 1991 Load: 32.7 t ADT: 21

LOCAL

Good

Over: CREEK

087412604, Ida, IA

Built 1996 Load: 32.7 t ADT: 72

M31 (QUAIL AVE)

Good

Over: UNNAMED CREEK

088390102, Ida, IA

Built 2012 Load: 32.7 t ADT: 369

LOCAL

Good

Over: SILVER CREEK

088391002, Ida, IA

Built 1998 Load: 32.7 t ADT: 30

170TH ST

Good

Over: SMALL STREAM

088400701, Ida, IA

Built 2022 Load: 32.7 t ADT: 21

LOCAL

Good

Over: BRANCH BECON CREEK

088410602, Ida, IA

Built 2002 Load: 32.7 t ADT: 15

LOCAL

Good

Over: SMALL STREAM

088411401, Ida, IA

Built 1998 Load: 32.7 t ADT: 15

LOCAL

Good

Over: CREEK

088413002, Ida, IA

Built 1992 Load: 32.7 t ADT: 34

FM

Good

Over: UNNAMED CREEK

089393001, Ida, IA

Built 2005 Load: 32.7 t ADT: 609

LOCAL

Good

Over: SILVER CREEK

089400301, Ida, IA

Built 1989 Load: 32.7 t ADT: 50

120TH ST

Good

Over: CREEK

089401701, Ida, IA

Built 2000 Load: 32.7 t ADT: 72

FM

Good

Over: SILVER CREEK

089402201, Ida, IA

Built 2004 Load: 32.7 t ADT: 210

LOCAL

Good

Over: ASHTON CREEK TRIB

089410305, Ida, IA

Built 1991 Load: 32.7 t ADT: 21

FM

Good

Over: SMALL STREAM

088413402, Ida, IA

Built 1991 Load: 32.7 t ADT: 45

260TH STREET

Good

Over: BADGER CREEK

087402603, Ida, IA

Built 2008 Load: 32.7 t ADT: 11

IA 149

Good

Over: BRANCH OLD MANS CREEK

0.9 mi. S of Jct. SR F46, Iowa, IA

Built 1985 Load: 32.7 t ADT: 1,910

LOCAL

Good

Over: TEENER CREEK

078093203, Iowa, IA

Built 1990 Load: 32.7 t ADT: 15

LOCAL

Good

Over: OLD MAN'S CREEK

078100201, Iowa, IA

Built 2003 Load: 32.7 t ADT: 90

LOCAL

Good

Over: BR NORTH ENGLISH RIVER

078110201, Iowa, IA

Built 2005 Load: 32.7 t ADT: 40

FM

Good

Over: NORTH FORK ENGLISH RIVER

078110302, Iowa, IA

Built 2006 Load: 32.7 t ADT: 70

Y AVE

Good

Over: BRANCH BRADLEY CREEK

079091304, Iowa, IA

Built 2003 Load: 32.7 t ADT: 20

LOCAL

Good

Over: BRANCH BRADLY CREEK

079091405, Iowa, IA

Built 2003 Load: 32.7 t ADT: 11

LOCAL

Good

Over: DRAINAGE DITCH

079091804, Iowa, IA

Built 2002 Load: 32.7 t ADT: 50

LOCAL

Good

Over: BRANCH OLD MANS CREEK

079093603, Iowa, IA

Built 2001 Load: 32.7 t ADT: 26

LOCAL

Good

Over: SMALL STREAM

080091702, Iowa, IA

Built 2001 Load: 32.7 t ADT: 60

Showing 11,651-11,700 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.