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

TIMBER AVE

Good

Over: BEAVER CREEK

099152902, Mitchell, IA

Built 2000 Load: 32.7 t ADT: 49

QUAIL AVE

Good

Over: CREEK

099160202, Mitchell, IA

Built 2000 Load: 32.7 t ADT: 59

QUAIL AVE

Good

Over: CREEK

099161102, Mitchell, IA

Built 2000 Load: 32.7 t ADT: 79

MARCH AVE

Good

Over: BURR OAK CREEK

099163002, Mitchell, IA

Built 1996 Load: 32.7 t ADT: 33

T28 HICKORY AVE

Good

Over: TURTLE CREEK

United States, Mitchell, IA

Built 2013 Load: 32.7 t ADT: 33

ZINNIA AVE

Good

Over: DEER CREEK

099180604, Mitchell, IA

Built 1999 Load: 32.7 t ADT: 167

ECHO AVE

Good

Over: WILLOW CREEK

099182602, Mitchell, IA

Built 2005 Load: 32.7 t ADT: 70

CAMEO AVE

Good

Over: WILLOW CREEK

099182802, Mitchell, IA

Built 2005 Load: 32.7 t ADT: 59

490TH

Good

Over: WAPSIPINICON RIVER

100152001, Mitchell, IA

Built 1997 Load: 32.7 t ADT: 15

UNDERWOOD AVE

Good

Over: CREEK

100152102, Mitchell, IA

Built 1997 Load: 32.7 t ADT: 26

480TH ST

Good

Over: DRAINAGE

100172801, Mitchell, IA

Built 1997 Load: 32.7 t ADT: 44

HICKORY AVE

Good

Over: DRAINAGE

100173206, Mitchell, IA

Built 1993 Load: 32.7 t ADT: 196

EPIC AVE

Good

Over: CREEK

100182306, Mitchell, IA

Built 1995 Load: 32.7 t ADT: 59

MARCH AVE

Good

Over: SPRING CREEK

098170702, Mitchell, IA

Built 2009 Load: 32.7 t ADT: 138

LOCAL

Good

Over: NORWAY CREEK

082420602, Monona, IA

Built 2010 Load: 32.7 t ADT: 29

SUMAC AVE

Good

Over: SKINNER CREEK

083422202, Monona, IA

Built 2008 Load: 32.7 t ADT: 45

105TH ST

Good

Over: DUTCH CREEK

085430203, Monona, IA

Built 2012 Load: 32.7 t ADT: 29

E 34

Good

Over: JORDAN CREEK

084432503, Monona, IA

Built 2012 Load: 32.7 t ADT: 259

FM

Good

Over: LOCAL CREEK

071162702, Monroe, IA

Built 2004 Load: 32.7 t ADT: 80

T41 695TH AVE

Good

Over: WHITE ASH BRANCH

072160804, Monroe, IA

Built 2022 Load: 32.7 t ADT: 26

H35 (189TH ST)

Good

Over: STREAM

072162003, Monroe, IA

Built 2013 Load: 32.7 t ADT: 140

196TH ST

Good

Over: STREAM

072172004, Monroe, IA

Built 2003 Load: 32.7 t ADT: 350

FM

Good

Over: CREEK

072181110, Monroe, IA

Built 2006 Load: 32.7 t ADT: 70

FM

Good

Over: WHIPPOORWILL CREEK

073192301, Monroe, IA

Built 2002 Load: 32.7 t ADT: 45

SR N18 (T AVE)

Good

Over: TRIB W NODAWAY RIVER

071360406, Montgomery, IA

Built 2011 Load: 32.7 t ADT: 40

FM

Good

Over: NISHNABOTNA RIVER

072382913, Montgomery, IA

Built 2002 Load: 32.7 t ADT: 761

LOCAL

Good

Over: DRAINAGE DITCH 2

076040601, Muscatine, IA

Built 2004 Load: 32.7 t ADT: 15

LOCAL

Good

Over: PIKE RUN CREEK

077030903, Muscatine, IA

Built 2003 Load: 32.7 t ADT: 40

LOCAL

Good

Over: YELLOW CREEK

077031704, Muscatine, IA

Built 2004 Load: 32.7 t ADT: 60

FM

Good

Over: HONEY CREEK

077042901, Muscatine, IA

Built 2003 Load: 32.7 t ADT: 20

110TH ST

Good

Over: CREEK

078010901, Muscatine, IA

Built 2010 Load: 32.7 t ADT: 227

110TH ST

Good

Over: CREEK

078011001, Muscatine, IA

Built 2011 Load: 32.7 t ADT: 227

LOCAL

Good

Over: CREEK

078012604, Muscatine, IA

Built 1996 Load: 32.7 t ADT: 82

LOCAL

Good

Over: CREEK

078023206, Muscatine, IA

Built 2004 Load: 32.7 t ADT: 80

FM

Good

Over: CREEK

078041503, Muscatine, IA

Built 2001 Load: 32.7 t ADT: 890

FM

Good

Over: SMALL STREAM

078041506, Muscatine, IA

Built 2001 Load: 32.7 t ADT: 850

FM

Good

Over: GOSHIEN DRAINAGE DITCH

078043601, Muscatine, IA

Built 2010 Load: 32.7 t ADT: 110

US 61 NB

Good

Over: MUSCATINE SLOUGH

6.7 mi. N of S Jct IA 92, Muscatine, IA

Built 2002 Load: 32.7 t ADT: 3,500

US 61 SB

Good

Over: MUSCATINE SLOUGH

6.7 mi. N of S Jct IA 92, Muscatine, IA

Built 2002 Load: 32.7 t ADT: 3,500

LOCAL SEC RD

Good

Over: LANGE CREEK SOUTH

094422601, O'Brien, IA

Built 1969 Load: 32.7 t ADT: 5

FM

Good

Over: SMALL UN-NAMED CREEK

097391302, O'Brien, IA

Built 1969 Load: 32.7 t ADT: 26

LOCAL SEC RD

Good

Over: SEWER CREEK

097393502, O'Brien, IA

Built 1991 Load: 32.7 t ADT: 26

LOCAL

Good

Over: FLOYD RIVER

097401801, O'Brien, IA

Built 1982 Load: 32.7 t ADT: 21

FM

Good

Over: WOLF CREEK

097420801, O'Brien, IA

Built 1966 Load: 32.7 t ADT: 469

LOCAL

Good

Over: WOLF CREEK

097421901, O'Brien, IA

Built 1900 Load: 32.7 t ADT: 26

LOCAL

Good

Over: STREAM

099423501, Osceola, IA

Built 2001 Load: 32.7 t ADT: 50

LOCAL

Good

Over: SMALL STREAM

099422602, Osceola, IA

Built 2001 Load: 32.7 t ADT: 26

IA 60

Good

Over: DRAINAGE DITCH

2.6 mi. N of Jct SR B14, Osceola, IA

Built 2004 Load: 32.7 t ADT: 2,550

M AVENUE

Good

Over: STREAM

067371802, Page, IA

Built 1996 Load: 32.7 t ADT: 20

J 52 (270TH ST)

Good

Over: LONG BRANCH

067380201, Page, IA

Built 2012 Load: 32.7 t ADT: 319

Showing 11,951-12,000 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.