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: OVER FLOW

0984623, Lyon, IA

Built 2004 Load: 32.7 t ADT: 62

LOCAL RD

Good

Over: ARGO SLOUGH

099431201, Lyon, IA

Built 2003 Load: 32.7 t ADT: 35

LOCAL ROAD

Good

Over: TAFT CREEK

099432701, Lyon, IA

Built 1992 Load: 32.7 t ADT: 26

LOCAL ROAD

Good

Over: ZOAR CREEK

099433402, Lyon, IA

Built 1992 Load: 32.7 t ADT: 46

FM

Good

Over: EMERY CREEK

099442001, Lyon, IA

Built 1978 Load: 32.7 t ADT: 40

LOCAL ROAD

Good

Over: TURNER CREEK

100441101, Lyon, IA

Built 2006 Load: 32.7 t ADT: 62

LOCAL ROAD

Good

Over: SMALL STREAM

100450902, Lyon, IA

Built 1989 Load: 32.7 t ADT: 26

K14 BUCHANAN AVE

Good

Over: BLOOD RUN CREEK

100481302, Lyon, IA

Built 2019 Load: 32.7 t ADT: 50

FM

Good

Over: SMALL STREAM

099451301, Lyon, IA

Built 1990 Load: 32.7 t ADT: 30

LOCAL

Good

Over: SMALL STREAM

100463201, Lyon, IA

Built 1990 Load: 32.7 t ADT: 81

LOCAL

Good

Over: SMALL STREAM

099441701, Lyon, IA

Built 1991 Load: 32.7 t ADT: 26

LOCAL

Good

Over: SMALL STREAM

099453101, Lyon, IA

Built 1991 Load: 32.7 t ADT: 26

LOCAL ROAD

Good

Over: TRIB TO MUD CREEK

099460202, Lyon, IA

Built 2004 Load: 32.7 t ADT: 112

LOCAL ROAD

Good

Over: TRIB TO MUD CREEK

099461001, Lyon, IA

Built 2004 Load: 32.7 t ADT: 46

LOCAL ROAD

Good

Over: TRIB TO MUD CREEK

100460904, Lyon, IA

Built 2004 Load: 32.7 t ADT: 26

LOCAL ROAD

Good

Over: SMALL

100483302, Lyon, IA

Built 2004 Load: 32.7 t ADT: 62

140TH ST

Good

Over: DRY RUN CREEK

100443501, Lyon, IA

Built 2005 Load: 32.7 t ADT: 20

KENNEDY AVE

Good

Over: DRY RUN CREEK

100443602, Lyon, IA

Built 2005 Load: 32.7 t ADT: 35

BUCHANAN AVE

Good

Over: MCLAREN CREEK

098481202, Lyon, IA

Built 1992 Load: 32.7 t ADT: 35

US 169

Good

Over: SOUTH CLANTON CREEK

3.0 MI. S OF SR G-61, Madison, IA

Built 1974 Load: 32.7 t ADT: 1,230

LOCAL

Good

Over: DRAINAGE

074281203, Madison, IA

Built 2007 Load: 32.7 t ADT: 11

FM

Good

Over: DRAINAGE DITCH

074291301, Madison, IA

Built 1992 Load: 32.7 t ADT: 477

UPLAND TRAIL

Good

Over: DRAINAGE

076260404, Madison, IA

Built 2015 Load: 32.7 t ADT: 45

LOCAL RD

Good

Over: NORTH RIVER

076270304, Madison, IA

Built 2007 Load: 32.7 t ADT: 50

FM

Good

Over: NORTH RIVER

077273607, Madison, IA

Built 1993 Load: 32.7 t ADT: 880

IVY AVE

Good

Over: DRAINAGE

077280406, Madison, IA

Built 2020 Load: 32.7 t ADT: 360

HOGBACK BRIDGE RD

Good

Over: NORTH RIVER

076281406, Madison, IA

Built 1992 Load: 32.7 t ADT: 131

LOCAL RD

Good

Over: OVERFLOW N RIVER

076270304, Madison, IA

Built 2007 Load: 32.7 t ADT: 50

MERINO AVE

Good

Over: DRAINAGE

074150704, Mahaska, IA

Built 2012 Load: 32.7 t ADT: 90

LOCAL

Good

Over: CEDAR CREEK

074151406, Mahaska, IA

Built 1985 Load: 32.7 t ADT: 30

LOCAL

Good

Over: DRAINAGE

074151804, Mahaska, IA

Built 1998 Load: 32.7 t ADT: 80

NEWPORT AVE

Good

Over: SPRING CREEK

075150510, Mahaska, IA

Built 2006 Load: 32.7 t ADT: 150

255TH ST

Good

Over: SPRING CREEK

075152103, Mahaska, IA

Built 2012 Load: 32.7 t ADT: 90

FM

Good

Over: SPRING CREEK

075152705, Mahaska, IA

Built 2003 Load: 32.7 t ADT: 130

FM

Good

Over: PAINTER CREEK

075160201, Mahaska, IA

Built 2010 Load: 32.7 t ADT: 150

245TH ST

Good

Over: DRAINAGE

075161707, Mahaska, IA

Built 2003 Load: 32.7 t ADT: 131

FM

Good

Over: MUCHAKINOCK CREEK

075162709, Mahaska, IA

Built 2001 Load: 32.7 t ADT: 620

FM

Good

Over: LITTLE MUCHAKINOCK CREEK

075163502, Mahaska, IA

Built 2007 Load: 32.7 t ADT: 200

LOCAL

Good

Over: ST JOSEPH CREEK

075171406, Mahaska, IA

Built 2003 Load: 32.7 t ADT: 50

FM

Good

Over: ST JOSEPH CREEK

075172406, Mahaska, IA

Built 1999 Load: 32.7 t ADT: 160

LOCAL

Good

Over: ST JOSEPH CREEK

075172505, Mahaska, IA

Built 1994 Load: 32.7 t ADT: 50

LOCAL

Good

Over: CEDAR CREEK

076140101, Mahaska, IA

Built 1993 Load: 32.7 t ADT: 5

200TH ST

Good

Over: DRAINAGE

076143001, Mahaska, IA

Built 2011 Load: 32.7 t ADT: 20

LOCAL

Good

Over: STREAM

076150502, Mahaska, IA

Built 1983 Load: 32.7 t ADT: 50

FM

Good

Over: DRAINAGE

076162503, Mahaska, IA

Built 1989 Load: 32.7 t ADT: 80

FM

Good

Over: BLACK OAK CREEK

076171002, Mahaska, IA

Built 2003 Load: 32.7 t ADT: 170

LOCAL

Good

Over: MUCHAKINOCK CREEK

076172001, Mahaska, IA

Built 1999 Load: 32.7 t ADT: 34

LOCAL

Good

Over: PLEASANT CREEK

077142201, Mahaska, IA

Built 1998 Load: 32.7 t ADT: 60

FM

Good

Over: BALLINGER CREEK

077163204, Mahaska, IA

Built 2010 Load: 32.7 t ADT: 50

OLD IA 102

Good

Over: SOUTH SKUNK RIVER

077172812, Mahaska, IA

Built 1990 Load: 32.7 t ADT: 2,340

Showing 11,851-11,900 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.