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: BRANCH RACCOON RIVER

091363604, Buena Vista, IA

Built 2004 Load: 32.7 t ADT: 30

LOCAL

Good

Over: BR MAPLE CREEK

092380602, Buena Vista, IA

Built 2004 Load: 32.7 t ADT: 30

LOCAL

Good

Over: BR RACCOON RIVER

093351705, Buena Vista, IA

Built 1998 Load: 32.7 t ADT: 80

FM

Good

Over: CREEK

093360407, Buena Vista, IA

Built 2001 Load: 32.7 t ADT: 300

FM

Good

Over: SMALL STREAM

091362202, Buena Vista, IA

Built 1999 Load: 32.7 t ADT: 450

BLUFF ST

Good

Over: STREAM

093370503, Buena Vista, IA

Built 2006 Load: 32.7 t ADT: 65

SINCLAIR AVE

Good

Over: SMALL STREAM

090160302, Butler, IA

Built 2000 Load: 32.7 t ADT: 638

FM

Good

Over: SMALL STREAM

090181002, Butler, IA

Built 2009 Load: 32.7 t ADT: 501

SINCLAIR AVE

Good

Over: SMALL STREAM

091160302, Butler, IA

Built 2000 Load: 32.7 t ADT: 579

FM

Good

Over: SMALL STREAM

091181002, Butler, IA

Built 1992 Load: 32.7 t ADT: 579

DOUGLAS AVE.

Good

Over: SMALL STREAM

091183402, Butler, IA

Built 1992 Load: 32.7 t ADT: 501

C33

Good

Over: SMALL STREAM

092161701, Butler, IA

Built 1993 Load: 32.7 t ADT: 609

C 25 170TH ST

Good

Over: SMALL STREAM

App. 2200 W. of Hwy 14, Butler, IA

Built 2019 Load: 32.7 t ADT: 69

FM

Good

Over: SMALL STREAM

092171903, Butler, IA

Built 2005 Load: 32.7 t ADT: 304

FM

Good

Over: KILSON CREEK

092172001, Butler, IA

Built 2005 Load: 32.7 t ADT: 304

FLOYD LINE ST

Good

Over: SMALL CREEK

093180301, Butler, IA

Built 2003 Load: 32.7 t ADT: 15

YALE AVE

Good

Over: SMALL STREAM

092153602, Butler, IA

Built 2008 Load: 32.7 t ADT: 334

C 25 170TH ST

Good

Over: SMALL STREAM

092171101, Butler, IA

Built 2019 Load: 32.7 t ADT: 69

270TH ST

Good

Over: CAMP CREEK

088343501, Calhoun, IA

Built 2005 Load: 32.7 t ADT: 609

FM

Good

Over: RACOON RIVER

086342203, Calhoun, IA

Built 1987 Load: 32.7 t ADT: 110

FM

Good

Over: DD NO. 46

087342202, Calhoun, IA

Built 2004 Load: 32.7 t ADT: 40

LOCAL

Good

Over: DD#81

089343102, Calhoun, IA

Built 1986 Load: 32.7 t ADT: 11

US 20

Good

Over: W FORK CAMP CREEK

3.1 mi. E of SR N28, Calhoun, IA

Built 2010 Load: 32.7 t ADT: 5,900

US 20 WB

Good

Over: CC RR

4.0 mi. E of Jct. SR N65, Calhoun, IA

Built 2011 Load: 32.7 t ADT: 3,450

US 20 EB

Good

Over: CC RR

4.0 mi. E of Jct. SR N65, Calhoun, IA

Built 2010 Load: 32.7 t ADT: 3,450

US 20

Good

Over: DD 9 & 13

3.0 mi. E of Jct. IA 4, Calhoun, IA

Built 2008 Load: 32.7 t ADT: 6,900

FM

Good

Over: SMALL STREAM

082352502, Carroll, IA

Built 1987 Load: 32.7 t ADT: 150

GRANT RD

Good

Over: MIDDLE RACCOON RIVER

000000000, Carroll, IA

Built 1986 Load: 32.7 t ADT: 3,914

FM

Good

Over: MIDDLE RACOON RIVER

085362601, Carroll, IA

Built 1971 Load: 32.7 t ADT: 20

310TH ST

Good

Over: SMALL STREAM

082332301, Carroll, IA

Built 1972 Load: 32.7 t ADT: 71

BASS STREET

Good

Over: LATERAL #77 DD #23

000000000, Carroll, IA

Built 2001 Load: 32.7 t ADT: 188

G 30 WHITE POLE RD

Good

Over: SMALL STREAM

077342203, Cass, IA

Built 1993 Load: 32.7 t ADT: 1,564

FM - JACKSON

Good

Over: CREEK

076342101, Cass, IA

Built 1999 Load: 32.7 t ADT: 131

JACKSON ST

Good

Over: STREAM

075352702, Cass, IA

Built 2007 Load: 32.7 t ADT: 481

LAKE ANITA PARK

Good

Over: STREAM

0.2 MI. W OF JCT. IA 148, Cass, IA

Built 1966 Load: 32.7 t

230 TH ST

Good

Over: STREAM

080011201, Cedar, IA

Built 2007 Load: 32.7 t ADT: 71

240TH ST

Good

Over: SUGAR CREEK

080011801, Cedar, IA

Built 1995 Load: 32.7 t ADT: 60

UNION AVE

Good

Over: SUGAR CREEK

080012802, Cedar, IA

Built 2000 Load: 32.7 t ADT: 970

F28 (BAKER AVE)

Good

Over: GOWER CREEK

080040502, Cedar, IA

Built 2012 Load: 32.7 t ADT: 950

LOCAL

Good

Over: NICHOLSON CREEK

080041901, Cedar, IA

Built 2003 Load: 32.7 t ADT: 72

FM

Good

Over: SMALL

081010210, Cedar, IA

Built 2004 Load: 32.7 t ADT: 740

HOOVER HWY

Good

Over: LIZARD CREEK

081011606, Cedar, IA

Built 2011 Load: 32.7 t ADT: 480

270TH ST

Good

Over: ROCK CREEK

081013501, Cedar, IA

Built 2010 Load: 32.7 t ADT: 60

FM

Good

Over: ROCK RUN CREEK

081030602, Cedar, IA

Built 1996 Load: 32.7 t ADT: 1,300

GRANT AVE

Good

Over: SMALL

081031908, Cedar, IA

Built 1998 Load: 32.7 t ADT: 40

FM

Good

Over: ROCK RUN CREEK

081033101, Cedar, IA

Built 2008 Load: 32.7 t ADT: 1,350

FM

Good

Over: ROCK RUN CREEK

081040101, Cedar, IA

Built 2004 Load: 32.7 t ADT: 90

FOX AVE

Good

Over: ROCK RUN CREEK

081040104, Cedar, IA

Built 1991 Load: 32.7 t ADT: 34

CIDER AVE

Good

Over: COON CR

081040404, Cedar, IA

Built 1998 Load: 32.7 t ADT: 11

DIXON AVE

Good

Over: BALDWIN CREEK

081041508, Cedar, IA

Built 2002 Load: 32.7 t ADT: 45

Showing 11,201-11,250 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.