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

LITTLE 4 MI CRK DR

Good

Over: E FOUR MILE CREEK

078230400, Polk, IA

Built 2004 Load: 32.7 t ADT: 2,740

NORTH JAMES ST

Good

Over: TRIB LITTLE BEAVER CREEK

080253200, Polk, IA

Built 2006 Load: 32.7 t ADT: 5,988

N PARK ST

Good

Over: LITTLE BEAVER CREEK

080252900, Polk, IA

Built 2007 Load: 32.7 t ADT: 288

SE 9TH ST

Good

Over: CRAWFORD CREEK

078241000, Polk, IA

Built 2010 Load: 32.7 t ADT: 465

E OVID AVENUE

Good

Over: 7TH WARD DITCH

079233000, Polk, IA

Built 1996 Load: 32.7 t ADT: 1,823

SW MAGAZINE RD

Good

Over: SAYLOR CREEK

080242701, Polk, IA

Built 2008 Load: 32.7 t ADT: 89

SW PRAIRIE TRL

Good

Over: SAYLOR CREEK

080242600, Polk, IA

Built 2013 Load: 32.7 t ADT: 344

N MAIN ST

Good

Over: CREEK

080253200, Polk, IA

Built 2002 Load: 32.7 t ADT: 143

64TH ST

Good

Over: DRAINAGE

T78N, R26W, S13, DAL CO, Polk, IA

Built 2009 Load: 32.7 t ADT: 43

IA 5 RAMP C NB

Good

Over: DRAINAGE

1.0 MILE S OF I-35 JUNCT, Polk, IA

Built 2000 Load: 32.7 t ADT: 1,220

I 35 NB

Good

Over: OVER UP RR

1.1 MILES N OF N JCT I-80, Polk, IA

Built 2002 Load: 32.7 t ADT: 45,700

E UNIVERSITY

Good

Over: SMALL CREEK

078230600, Polk, IA

Built 2003 Load: 32.7 t ADT: 27,200

US 275 & IA 92

Good

Over: MISSOURI RIVER AND RR

SOUTH OMAHA, Pottawattamie, IA

Built 2010 Load: 32.7 t ADT: 11,100

CO RD G18

Good

Over: BRANCH OF SILVER CREEK

077401507, Pottawattamie, IA

Built 1990 Load: 32.7 t ADT: 967

OLD LINCOLN HWY

Good

Over: STREAM

077440312, Pottawattamie, IA

Built 1989 Load: 32.7 t ADT: 1,175

GREENVIEW ROAD

Good

Over: STREAM

074430203, Pottawattamie, IA

Built 1978 Load: 32.7 t ADT: 1,254

400TH STREET

Good

Over: SMALL RUN

075401104, Pottawattamie, IA

Built 1979 Load: 32.7 t ADT: 50

400TH ST

Good

Over: DRAINAGE

075403404, Pottawattamie, IA

Built 2008 Load: 32.7 t ADT: 29

FM-MUDHOLLOW RD

Good

Over: INDIAN CREEK

075431824, Pottawattamie, IA

Built 1976 Load: 32.7 t ADT: 617

G30 MAHOGANY RD

Good

Over: NISHNABOTNA RIVER

076391803, Pottawattamie, IA

Built 2020 Load: 32.7 t ADT: 349

CREEK TOP RD

Good

Over: INDIAN CREEK

Creek Top, 10th to 9th St, Pottawattamie, IA

Built 2018 Load: 32.7 t ADT: 2,027

LOCAL

Good

Over: BUCK CREEK

078160303, Poweshiek, IA

Built 2006 Load: 32.7 t ADT: 11

FM

Good

Over: STREAM

079130802, Poweshiek, IA

Built 2006 Load: 32.7 t ADT: 40

142ND ST

Good

Over: STREAM

079140804, Poweshiek, IA

Built 2002 Load: 32.7 t ADT: 15

430TH AVE

Good

Over: STREAM

079130701, Poweshiek, IA

Built 2022 Load: 32.7 t ADT: 30

180TH ST

Good

Over: STREAM

079142402, Poweshiek, IA

Built 2019 Load: 32.7 t ADT: 5

LOCAL

Good

Over: SUGAR CREEK

079162001, Poweshiek, IA

Built 2007 Load: 32.7 t ADT: 60

FM

Good

Over: LITTLE BEAR CREEK

080132002, Poweshiek, IA

Built 2008 Load: 32.7 t ADT: 45

FM

Good

Over: CUB CREEK

080132207, Poweshiek, IA

Built 1994 Load: 32.7 t ADT: 750

LOCAL

Good

Over: STREAM

080132304, Poweshiek, IA

Built 2006 Load: 32.7 t ADT: 26

FM

Good

Over: CUB CREEK

080132902, Poweshiek, IA

Built 2006 Load: 32.7 t ADT: 50

70TH ST

Good

Over: STREAM

080153104, Poweshiek, IA

Built 2020 Load: 32.7 t ADT: 26

FM

Good

Over: SMALL

080163502, Poweshiek, IA

Built 1983 Load: 32.7 t ADT: 45

J20 130TH ST

Good

Over: SIDE DITCH-SUNVALLEYCREE

070291905, Ringgold, IA

Built 2002 Load: 32.7 t ADT: 10

IA 2

Good

Over: DRAINAGE DITCH

1.5 mi. E of jct. SR P64, Ringgold, IA

Built 1976 Load: 32.7 t ADT: 1,550

300TH STREET

Good

Over: STREAM

067290803, Ringgold, IA

Built 2011 Load: 32.7 t ADT: 5

250TH ST

Good

Over: RUDER CREEK

068282401, Ringgold, IA

Built 2014 Load: 32.7 t ADT: 26

260TH ST

Good

Over: RUDER CREEK

068282403, Ringgold, IA

Built 2007 Load: 32.7 t ADT: 15

LOCAL

Good

Over: STREAM

068302801, Ringgold, IA

Built 1993 Load: 32.7 t ADT: 11

P20 (125TH AVE)

Good

Over: STREAM

068311604, Ringgold, IA

Built 2013 Load: 32.7 t ADT: 26

FM

Good

Over: LOTTS CREEK

069281601, Ringgold, IA

Built 2000 Load: 32.7 t ADT: 29

LOCAL

Good

Over: GOOSEBERRY CREEK

069291101, Ringgold, IA

Built 2006 Load: 32.7 t ADT: 26

FM

Good

Over: GOOSEBERRY CREEK

069291501, Ringgold, IA

Built 1993 Load: 32.7 t ADT: 79

FM

Good

Over: WALNUT CREEK

069293102, Ringgold, IA

Built 1992 Load: 32.7 t ADT: 270

LOCAL

Good

Over: PLUM CREEK

070300901, Ringgold, IA

Built 1997 Load: 32.7 t ADT: 11

LOCAL

Good

Over: LIME CREEK

086361702, Sac, IA

Built 1989 Load: 32.7 t ADT: 50

FM

Good

Over: INLET CREEK

086362209, Sac, IA

Built 1987 Load: 32.7 t ADT: 638

FM

Good

Over: DD #57

086362401, Sac, IA

Built 2007 Load: 32.7 t ADT: 628

FM

Good

Over: LIME CREEK

086362802, Sac, IA

Built 1999 Load: 32.7 t ADT: 529

FM

Good

Over: SMALL CREEK

086363002, Sac, IA

Built 2000 Load: 32.7 t ADT: 748

Showing 12,051-12,100 of 20,753 bridges

Related

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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.