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

Good

Over: WOLF CREEK

071212106, Lucas, IA

Built 2005 Load: 37.2 t ADT: 21

LOCAL RD

Good

Over: CREEK

071222904, Lucas, IA

Built 2002 Load: 37.2 t ADT: 26

NATURE TRAIL

Good

Over: CEDAR CREEK

076272106, Madison, IA

Built 2006 Load: 37.2 t ADT: 60

LOCAL RD

Good

Over: CEDAR CREEK

076272602, Madison, IA

Built 2002 Load: 37.2 t ADT: 71

FM

Good

Over: DM RIVER

074160504, Mahaska, IA

Built 2010 Load: 37.2 t ADT: 620

SHADOW AVE

Good

Over: LITTLE CEDAR RIVER

098160106, Mitchell, IA

Built 1995 Load: 37.2 t ADT: 49

485TH

Good

Over: CREEK

100181903, Mitchell, IA

Built 1974 Load: 37.2 t ADT: 33

SORRELL AVE

Good

Over: GINGER CREEK

095402901, O'Brien, IA

Built 2016 Load: 37.2 t ADT: 11

FM

Good

Over: OTTER CREEK

098421505, Osceola, IA

Built 2000 Load: 37.2 t ADT: 748

330TH ST

Good

Over: CREEK

090433501, Plymouth, IA

Built 2002 Load: 37.2 t ADT: 26

FM

Good

Over: FLOYD RIVER

092453105, Plymouth, IA

Built 2007 Load: 37.2 t ADT: 1,566

FM

Good

Over: MUD CREEK

078220903, Polk, IA

Built 1990 Load: 37.2 t ADT: 159

FM 158TH

Good

Over: LITTLE CREEK

081250801, Polk, IA

Built 1990 Load: 37.2 t ADT: 170

JUNIPER ROAD

Good

Over: MIDDLE SILVER CREEK

076413501, Pottawattamie, IA

Built 2002 Load: 37.2 t ADT: 34

175TH STREET

Good

Over: HONEY CREEK

077441306, Pottawattamie, IA

Built 1991 Load: 37.2 t ADT: 60

170TH STREET

Good

Over: HONEY DITCH CREEK

077442404, Pottawattamie, IA

Built 1995 Load: 37.2 t ADT: 139

LOCAL

Good

Over: WALNUT CREEK

081141504, Poweshiek, IA

Built 1989 Load: 37.2 t ADT: 45

LOCAL

Good

Over: WALL LAKE INLET

086363602, Sac, IA

Built 2002 Load: 37.2 t ADT: 34

LOCAL

Good

Over: SILVER CREEK

078403411, Shelby, IA

Built 2001 Load: 37.2 t ADT: 82

FM

Good

Over: W. NISHNABOTNA RIVER

081371003, Shelby, IA

Built 1992 Load: 37.2 t ADT: 15

LOCAL

Good

Over: SIX MILE CREEK

094482602, Sioux, IA

Built 1990 Load: 37.2 t ADT: 45

282ND ST

Good

Over: WALNUT CREEK

082240104, Story, IA

Built 2002 Load: 37.2 t ADT: 80

LOCAL RD

Good

Over: STREAM

073311804, Union, IA

Built 2000 Load: 37.2 t ADT: 11

LOCAL

Good

Over: LIZARD CREEK

089293003, Webster, IA

Built 2004 Load: 37.2 t ADT: 41

LOCAL ROAD

Good

Over: CREEK

100090802, Winneshiek, IA

Built 1991 Load: 37.2 t ADT: 49

361ST ST

Good

Over: DRAINAGE

100092409, Winneshiek, IA

Built 1997 Load: 37.2 t ADT: 44

COTTER RD

Good

Over: TRIB TO MILLER CREEK

87-12-04-02-20, Black Hawk, IA

Built 2019 Load: 37.3 t ADT: 59

COTTER RD

Good

Over: MUD CREEK

87-12-21-02-10, Black Hawk, IA

Built 2013 Load: 37.3 t ADT: 5

HESS RD

Good

Over: TRIB TO MILLER CREEK

87-13-01-02-10, Black Hawk, IA

Built 2020 Load: 37.3 t ADT: 29

ANSBOROUGH AVE

Good

Over: TRIB TO MILLER CREEK

87-13-09-02-10, Black Hawk, IA

Built 2010 Load: 37.3 t ADT: 15

E QUARRY RD

Good

Over: TRIB TO MILLER CREEK

87-13-14-01-10, Black Hawk, IA

Built 2021 Load: 37.3 t ADT: 39

HAMMOND AVE

Good

Over: TRIB TO MILLER CREEK

87-13-14-02-10, Black Hawk, IA

Built 2021 Load: 37.3 t ADT: 15

LINCOLN ROAD

Good

Over: TRIB TO BLACK HAWK CREEK

87-14-10-02-10, Black Hawk, IA

Built 2022 Load: 37.3 t ADT: 97

YOUNG RD

Good

Over: TRIB TO INDIAN CREEK

88-11-08-03-10, Black Hawk, IA

Built 2011 Load: 37.3 t ADT: 59

FOULK RD

Good

Over: TRIB TO MILLER CREEK

88-12-29-02-10, Black Hawk, IA

Built 2015 Load: 37.3 t ADT: 49

W ORANGE RD

Good

Over: PRESCOTTS CREEK

88-13-20-01-10, Black Hawk, IA

Built 2013 Load: 37.3 t ADT: 59

WATTERS RD

Good

Over: TRIB TO BLACK HAWK CREEK

88-14-29-05-10, Black Hawk, IA

Built 2017 Load: 37.3 t ADT: 285

NEWELL ST

Good

Over: POYNER CREEK

89-11-20-01-10, Black Hawk, IA

Built 2014 Load: 37.3 t ADT: 29

E AIRLINE HWY

Good

Over: VIRDEN CREEK

89-12-07-01-10, Black Hawk, IA

Built 2016 Load: 37.3 t ADT: 118

E DONALD ST

Good

Over: TRIB TO ELK RUN CREEK

89-12-13-01-10, Black Hawk, IA

Built 2012 Load: 37.3 t ADT: 108

S UNION RD

Good

Over: TRIB TO DRY RUN CREEK

89-14-27-04-10, Black Hawk, IA

Built 1994 Load: 37.3 t ADT: 1,149

E GRESHAM RD

Good

Over: TRIB TO CRANE CREEK

90-11-07-01-10, Black Hawk, IA

Built 2018 Load: 37.3 t ADT: 15

E MARQUIS RD

Good

Over: TRIB TO CRANE CREEK

90-12-03-01-30, Black Hawk, IA

Built 2016 Load: 37.3 t ADT: 49

WEST BENNINGTON RD

Good

Over: TRIB TO CEDAR RIVER

90-13-21-01-05, Black Hawk, IA

Built 2020 Load: 37.3 t ADT: 29

W WASHBURN RD

Good

Over: PRESCOTTS CREEK

88-13-29-01-05, Black Hawk, IA

Built 2022 Load: 37.3 t ADT: 39

C26 170TH ST

Good

Over: STREAM

092130901, Bremer, IA

Built 2015 Load: 37.3 t ADT: 39

LOCAL

Good

Over: SMALL STREAM

093180303, Butler, IA

Built 2000 Load: 37.3 t ADT: 15

LOCAL

Good

Over: WILLEY BRANCH

083342902, Carroll, IA

Built 1996 Load: 37.3 t ADT: 15

345TH ST

Good

Over: STREAM

096381203, Clay, IA

Built 2002 Load: 37.3 t ADT: 15

Y44 (170TH AVE)

Good

Over: DRAINAGE DITCH 20

082E22002, Clinton, IA

Built 2012 Load: 37.3 t ADT: 470

Showing 13,401-13,450 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.