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

US 169

Good

Over: STREAM

3.0 mi. N of jct. IA 7, Webster, IA

Built 1959 Load: 90.5 t ADT: 5,100

SILVER CK RD

Good

Over: TRIB TO SILVER CREEK

086052401, Linn, IA

Built 2002 Load: 91.7 t ADT: 15

260TH AVE

Good

Over: CREEK

082E31104, Clinton, IA

Built 2019 Load: 96.2 t ADT: 135

280TH ST

Good

Over: CREEK

081E23108, Clinton, IA

Built 2020 Load: 97.2 t ADT: 82

200TH AVE

Good

Over: DD

082E22602, Clinton, IA

Built 2017 Load: 97.2 t ADT: 60

280TH AVE

Good

Over: CREEK

082E41802, Clinton, IA

Built 2016 Load: 97.2 t ADT: 82

134TH ST

Good

Over: SMALL CREEK

085E32901, Jackson, IA

Built 2021 Load: 97.2 t ADT: 26

IA 136

Good

Over: STREAM

0.2 MI. N. OF CO. RD. E45, Jones, IA

Built 2022 Load: 97.2 t ADT: 670

LISBON BLVD

Good

Over: SPRING CREEK

0.4miNjctUS30&LisbonBLVD, Linn, IA

Built 2017 Load: 97.2 t ADT: 786

FONTANELLE RD

Good

Over: MIDDLE RIVER

77321709, Adair, IA

Built 2012 Load: 99.9 t ADT: 89

FM

Good

Over: MIDDLE NODAWAY RIVER BR.

077333001, Adair, IA

Built 2003 Load: 99.9 t ADT: 26

130TH ST

Good

Over: SMALL STREAM

77332080, Adair, IA

Built 2012 Load: 99.9 t ADT: 30

69TH ST

Good

Over: SMALL STREAM

083120901, Benton, IA

Built 2000 Load: 99.9 t ADT: 15

FM

Good

Over: BR WILDCAT CK

084103101, Benton, IA

Built 2001 Load: 99.9 t ADT: 15

LOCAL

Good

Over: BR WILD CAT CREEK

084102801, Benton, IA

Built 1997 Load: 99.9 t ADT: 44

LOCAL

Good

Over: BR. OF PRATT CREEK

086112601, Benton, IA

Built 1999 Load: 99.9 t ADT: 11

GRAIN RD

Good

Over: STREAM

T92, R4w, Sec5, Clayton, IA

Built 2014 Load: 99.9 t ADT: 11

NATURE AVE

Good

Over: SMALL STREAM

T91N,R2W,Sec5, Clayton, IA

Built 2014 Load: 99.9 t ADT: 11

110TH ST.

Good

Over: SCRAMBLING CREEK

083E70701, Clinton, IA

Built 1974 Load: 99.9 t ADT: 26

LOCAL

Good

Over: SMALL STREAM

085411402, Crawford, IA

Built 1962 Load: 99.9 t ADT: 62

I-80

Good

Over: PANTHER CREEK

0.6 mi. W of SR P58 & F90, Dallas, IA

Built 1965 Load: 99.9 t ADT: 32,100

180TH ST

Good

Over: TRIB N CHEQUEST LAKE CR

069130707, Davis, IA

Built 2015 Load: 99.9 t ADT: 11

IA 2 US 275

Good

Over: DRAINAGE

0.4 MI. S OF N JCT. IA 2, Fremont, IA

Built 2006 Load: 99.9 t ADT: 1,140

FM

Good

Over: DRAINAGE DITCH

087251108, Hamilton, IA

Built 2004 Load: 99.9 t ADT: 249

LOCAL

Good

Over: WHITE FOX CREEK

089251005, Hamilton, IA

Built 1989 Load: 99.9 t ADT: 26

IA 44

Good

Over: BRANCH SIX MILE CREEK

4.3 MI. E OF JCT. US 30, Harrison, IA

Built 1978 Load: 99.9 t ADT: 800

180TH ST

Good

Over: LITTLE WAPSIPINICON RVR

097140101, Howard, IA

Built 2003 Load: 99.9 t ADT: 51

180TH ST

Good

Over: DRAINAGE DITCH

097140301, Howard, IA

Built 2010 Load: 99.9 t ADT: 35

LOCAL BIRCH

Good

Over: BR UPPER IA RIVER

100140804, Howard, IA

Built 2008 Load: 99.9 t ADT: 135

LOCAL ELM AVE

Good

Over: BR STAFF CR

100142302, Howard, IA

Built 2005 Load: 99.9 t ADT: 73

LOCAL BIRCH AVE

Good

Over: STAFF CR

100142904, Howard, IA

Built 2008 Load: 99.9 t ADT: 39

JADE AVE

Good

Over: BR OF CRANE CREEK

099132702, Howard, IA

Built 2005 Load: 99.9 t ADT: 44

BUNKER HILL RD

Good

Over: BEERS CREEK

084011405, Jones, IA

Built 2019 Load: 99.9 t ADT: 11

FLEMINGVIL RD

Good

Over: EAST OTTER CREEK

085071006, Linn, IA

Built 1995 Load: 99.9 t ADT: 70

NELSON CK RD

Good

Over: NELSON CR

085082703, Linn, IA

Built 2003 Load: 99.9 t ADT: 39

INDIAN BRIDGE RD

Good

Over: EAST INDIAN CREEK

085063401, Linn, IA

Built 2001 Load: 99.9 t ADT: 20

FROZEN HILL RD

Good

Over: TRIB TO BUFFALO CREEK

085051202, Linn, IA

Built 2008 Load: 99.9 t ADT: 39

33RD AVE SW

Good

Over: UNNAMED TRIBUTARY

000000000, Linn, IA

Built 2006 Load: 99.9 t ADT: 10,700

LOCAL

Good

Over: HONEY CREEK

071202603, Lucas, IA

Built 2005 Load: 99.9 t ADT: 5

LOCAL

Good

Over: BR OF LITTLE WHITEBREAST

072210302, Lucas, IA

Built 2008 Load: 99.9 t ADT: 26

180TH TRL

Good

Over: BR OF CHARITON RIVER

071221604, Lucas, IA

Built 2009 Load: 99.9 t ADT: 11

ILLINOIS DR

Good

Over: TETER CREEK

076202201, Marion, IA

Built 2019 Load: 99.9 t ADT: 104

IA 92

Good

Over: DRAINAGE DITCH

2.8 mi. E of S jct. IA 5, Marion, IA

Built 1978 Load: 99.9 t ADT: 3,870

LOCAL

Good

Over: DRAINAGE

071381302, Montgomery, IA

Built 1990 Load: 99.9 t ADT: 15

LOCAL

Good

Over: NISHNABOTNA TRIB

073380204, Montgomery, IA

Built 1992 Load: 99.9 t ADT: 50

LOCAL

Good

Over: SMALL STREAM

094432102, Sioux, IA

Built 2003 Load: 99.9 t ADT: 15

LOCAL

Good

Over: SMALL STREAM

094432501, Sioux, IA

Built 2002 Load: 99.9 t ADT: 40

LOCAL

Good

Over: SMALL STREAM

094432601, Sioux, IA

Built 1990 Load: 99.9 t ADT: 5

LOCAL

Good

Over: SMALL CREEK

094440202, Sioux, IA

Built 1985 Load: 99.9 t ADT: 1,100

L12

Good

Over: NO NAME CREEK

094441206, Sioux, IA

Built 1982 Load: 99.9 t ADT: 133

Showing 16,451-16,500 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.