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: BIG CREEK

082251603, Boone, IA

Built 2004 Load: 48.2 t ADT: 30

LOCAL

Good

Over: EVERSOLL CREEK

082262101, Boone, IA

Built 2009 Load: 48.2 t ADT: 30

LOCAL

Good

Over: LITTLE BEAVER CREEK

082272901, Boone, IA

Built 2004 Load: 48.2 t ADT: 45

FM

Good

Over: LITTLE BEAVER CREEK

082273201, Boone, IA

Built 2003 Load: 48.2 t ADT: 40

FM 310TH ST.

Good

Over: SAND CREEK

087082101, Buchanan, IA

Built 1995 Load: 48.2 t ADT: 35

FM

Good

Over: PRARIE CREEK

089072201, Buchanan, IA

Built 2007 Load: 48.2 t ADT: 59

105TH ST

Good

Over: OTTER CREEK

090090407, Buchanan, IA

Built 2000 Load: 48.2 t ADT: 26

LOCAL

Good

Over: BR MAPLE CREEK

092383104, Buena Vista, IA

Built 1997 Load: 48.2 t ADT: 30

T43

Good

Over: ALRY RUN CREEK

092161706, Butler, IA

Built 2006 Load: 48.2 t ADT: 442

FM

Good

Over: PURGATORY CREEK

086322004, Calhoun, IA

Built 1992 Load: 48.2 t ADT: 40

LOCAL

Good

Over: CEDAR CREEK

087310202, Calhoun, IA

Built 1994 Load: 48.2 t ADT: 40

LOCAL

Good

Over: LAKE CREEK

087321902, Calhoun, IA

Built 1992 Load: 48.2 t ADT: 110

LOCAL

Good

Over: LIZARD CREEK

089311101, Calhoun, IA

Built 1991 Load: 48.2 t ADT: 40

LOCAL - QUINCY

Good

Over: CREEK

075362801, Cass, IA

Built 2003 Load: 48.2 t ADT: 15

TAYLOR AVE

Good

Over: STREAM

080012002, Cedar, IA

Built 2006 Load: 48.2 t ADT: 26

FM

Good

Over: NICHOLSON CREEK

080041504, Cedar, IA

Built 1998 Load: 48.2 t ADT: 60

FM

Good

Over: GOWER CREEK

081043208, Cedar, IA

Built 1994 Load: 48.2 t ADT: 70

US 18 WB

Good

Over: UPRR

0.7 mi. E of Jct. U.S. 65, Cerro Gordo, IA

Built 1999 Load: 48.2 t ADT: 5,250

FM-W AVE.

Good

Over: MAPLE RIVER

092391402, Cherokee, IA

Built 2005 Load: 48.2 t ADT: 190

172ND STREET

Good

Over: ROBERTS CREEK

094050703, Clayton, IA

Built 1993 Load: 48.2 t ADT: 26

LOCAL

Good

Over: SLOUGH CREEK

081272801, Dallas, IA

Built 2003 Load: 48.2 t ADT: 30

310TH ST

Good

Over: ROBINSON CREEK

087061903, Delaware, IA

Built 2000 Load: 48.2 t ADT: 49

FM

Good

Over: CEDAR FORK FLINT CREEK

072032905, Des Moines, IA

Built 2006 Load: 48.2 t ADT: 1,080

LOCAL

Good

Over: LYTLE CREEK

087E21704, Dubuque, IA

Built 1997 Load: 48.2 t ADT: 60

LOCAL ROAD

Good

Over: RK BEAVER CREEK

088180602, Grundy, IA

Built 2002 Load: 48.2 t ADT: 59

LOCAL

Good

Over: CREEK

086241102, Hamilton, IA

Built 2006 Load: 48.2 t ADT: 71

M AVE

Good

Over: HONEY CREEK

086211202, Hardin, IA

Built 2000 Load: 48.2 t ADT: 62

PERKINS RD

Good

Over: MUD CREEK

070052704, Henry, IA

Built 2006 Load: 48.2 t ADT: 91

FM

Good

Over: ELK CREEK

088393602, Ida, IA

Built 2003 Load: 48.2 t ADT: 369

FM 240TH AVE

Good

Over: NORTH BUFFALO CREEK

098272402, Kossuth, IA

Built 2007 Load: 48.2 t ADT: 330

FM

Good

Over: OTTER CREEK

073040206, Louisa, IA

Built 1992 Load: 48.2 t ADT: 490

LOCAL

Good

Over: BUCK CREEK

077150501, Mahaska, IA

Built 1996 Load: 48.2 t ADT: 34

LOCAL

Good

Over: BUCKLEY CREEK

077172203, Mahaska, IA

Built 1994 Load: 48.2 t ADT: 50

FM

Good

Over: THUNDER CREEK

077182606, Marion, IA

Built 2005 Load: 48.2 t ADT: 410

FM

Good

Over: BRUSH CREEK

082173401, Marshall, IA

Built 2002 Load: 48.2 t ADT: 442

LOCAL

Good

Over: OTTER CREEK

078020201, Muscatine, IA

Built 1996 Load: 48.2 t ADT: 280

FM

Good

Over: FLOYD RIVER

097410901, O'Brien, IA

Built 2001 Load: 48.2 t ADT: 71

FM

Good

Over: OCHEYEDAN RIVER

100412403, Osceola, IA

Built 1994 Load: 48.2 t ADT: 30

FM C-60

Good

Over: DRY BRANCH

090440901, Plymouth, IA

Built 1992 Load: 48.2 t ADT: 439

LAKE AVE

Good

Over: BIG WHISKEY CREEK

090450804, Plymouth, IA

Built 2002 Load: 48.2 t ADT: 71

180TH ST

Good

Over: BIG WHISKEY SLOUGH

092431401, Plymouth, IA

Built 2006 Load: 48.2 t ADT: 15

LOCAL

Good

Over: LOTTS CREEK

070291302, Ringgold, IA

Built 1994 Load: 48.2 t ADT: 15

LOCAL

Good

Over: STREAM

087360502, Sac, IA

Built 2005 Load: 48.2 t ADT: 40

115TH AVE

Good

Over: HICKORY CREEK

079E21308, Scott, IA

Built 1993 Load: 48.2 t ADT: 1,540

210TH ST

Good

Over: CREEK

079E43105, Scott, IA

Built 2004 Load: 48.2 t ADT: 2,740

LOCAL

Good

Over: SMALL STREAM

094431901, Sioux, IA

Built 2002 Load: 48.2 t ADT: 35

FM

Good

Over: DEEP CREEK

094432504, Sioux, IA

Built 1998 Load: 48.2 t ADT: 345

FM

Good

Over: NO NAME CREEK

096470801, Sioux, IA

Built 1990 Load: 48.2 t ADT: 80

B AVE

Good

Over: SUGAR CREEK

084162002, Tama, IA

Built 2005 Load: 48.2 t ADT: 20

FM

Good

Over: SALT CREEK

085142902, Tama, IA

Built 2003 Load: 48.2 t ADT: 128

Showing 15,601-15,650 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.