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

IA 14

Good

Over: STREAM

0.7 mi. N of N Jct SR C33, Butler, IA

Built 1994 Load: 36.7 t ADT: 1,740

FM

Good

Over: SMALL STREAM

090151602, Butler, IA

Built 1990 Load: 36.7 t ADT: 638

R70/580TH AVE

Good

Over: UNION 118 WIRE LK OUTLT

082231604, Story, IA

Built 1989 Load: 36.7 t ADT: 818

LOCAL ROAD

Good

Over: PAINTER CREEK

075252304, Warren, IA

Built 1997 Load: 36.7 t ADT: 51

FM

Good

Over: BEAVER CREEK

081340202, Audubon, IA

Built 1994 Load: 36.8 t ADT: 20

FM - 710TH

Good

Over: CROOKED CREEK

077351404, Cass, IA

Built 1988 Load: 36.8 t ADT: 5

LOCAL

Good

Over: CREEK

089410204, Ida, IA

Built 2010 Load: 36.8 t ADT: 5

E 116TH ST S

Good

Over: SMALL STREAM

078171904, Jasper, IA

Built 2017 Load: 36.8 t ADT: 25

J59 (610TH ST)

Good

Over: STREAM

067162303, Appanoose, IA

Built 2013 Load: 36.9 t ADT: 15

FM

Good

Over: CREEK

081363501, Audubon, IA

Built 2006 Load: 36.9 t ADT: 409

SB I-380

Good

Over: INDIAN CREEK

2.1 MI. S OF JCT. 20, Black Hawk, IA

Built 1984 Load: 36.9 t ADT: 8,450

FAWN HOLLOW

Good

Over: ROBERT'S CREEK

094053604, Clayton, IA

Built 1984 Load: 36.9 t ADT: 108

FM

Good

Over: W FK W NISHNABOTNA RIVER

082382606, Crawford, IA

Built 1990 Load: 36.9 t ADT: 190

LOCAL

Good

Over: PANTHER CREEK

078281603, Dallas, IA

Built 1989 Load: 36.9 t ADT: 110

FM 260TH AVE

Good

Over: PENNS BRANCH

088041102, Delaware, IA

Built 1995 Load: 36.9 t ADT: 236

IA 3

Good

Over: STREAM

0.1 mi. S of jct. SR D10, Dubuque, IA

Built 1974 Load: 36.9 t ADT: 5,100

MAPLE RD

Good

Over: CREEK

095092504, Fayette, IA

Built 2023 Load: 36.9 t ADT: 49

I 29 SB

Good

Over: PLUM CREEK

0.5 mi. S of Jct. SR J-24, Fremont, IA

Built 2009 Load: 36.9 t ADT: 6,100

N 65 D AVE

Good

Over: RACCOON RIVER

4.3 Mi N US30, Greene, IA

Built 2017 Load: 36.9 t ADT: 379

IA 141

Good

Over: DRY RUN CREEK

0.5 mi. E of Jct. SR P-18, Guthrie, IA

Built 2004 Load: 36.9 t ADT: 2,120

220TH ST

Good

Over: STREAM

071110203, Jefferson, IA

Built 2016 Load: 36.9 t ADT: 25

FM AMANA RD

Good

Over: STREAM

081082111, Johnson, IA

Built 1973 Load: 36.9 t ADT: 190

NB US 218

Good

Over: OLD MAN CREEK

0.7 mi S of S jct. SR F62, Johnson, IA

Built 1982 Load: 36.9 t ADT: 9,650

FM

Good

Over: SMALL STREAM

075043403, Louisa, IA

Built 1978 Load: 36.9 t ADT: 140

NB I-29

Good

Over: PONY CREEK

0.7 MILE N OF S JCT US 34, Mills, IA

Built 2011 Load: 36.9 t ADT: 6,800

SB I-29

Good

Over: PONY CREEK

0.7 MILE N OF S JCT US 34, Mills, IA

Built 2010 Load: 36.9 t ADT: 6,800

BROAD ST

Good

Over: SMALL NATURAL STREAM

000000000, Mitchell, IA

Built 2019 Load: 36.9 t ADT: 1,489

MARBLE AVE

Good

Over: WILLOW CREEK

092451104, Plymouth, IA

Built 1994 Load: 36.9 t ADT: 538

LOCAL ROAD

Good

Over: BRANCH FOUR MILE CREEK

081240402, Polk, IA

Built 1999 Load: 36.9 t ADT: 60

LOCAL

Good

Over: SMALL STREAM

081241402, Polk, IA

Built 1995 Load: 36.9 t ADT: 45

G30 MAHAGONY RD

Good

Over: SILVER CREEK

076401603, Pottawattamie, IA

Built 2016 Load: 36.9 t ADT: 349

ROSEWOOD ROAD

Good

Over: MIDDLE SILVER CREEK

076410103, Pottawattamie, IA

Built 2020 Load: 36.9 t ADT: 26

FM

Good

Over: SIX MILE CREEK

095462001, Sioux, IA

Built 1978 Load: 36.9 t ADT: 898

LOCAL

Good

Over: SMALL

094440902, Sioux, IA

Built 1940 Load: 36.9 t ADT: 2,930

140TH ST

Good

Over: MCELHANEY CREEK

089442701, Woodbury, IA

Built 1993 Load: 36.9 t ADT: 45

EAST MARQUIS RD

Good

Over: SMALL STREAM

090120501-10, Bremer, IA

Built 2017 Load: 37.0 t ADT: 44

190TH ST

Good

Over: SMALL STREAM

082E22101, Clinton, IA

Built 1992 Load: 37.0 t ADT: 420

210TH ST.

Good

Over: CREEK

082E53401, Clinton, IA

Built 1984 Load: 37.0 t ADT: 25

SB I-35

Good

Over: STREAM

2.0 mi. N of MO St. Line, Decatur, IA

Built 1970 Load: 37.0 t ADT: 7,100

LOCAL ROAD

Good

Over: BRANCH OF HAMMERS CREEK

089150301, Grundy, IA

Built 2007 Load: 37.0 t ADT: 29

190 150TH ST

Good

Over: BOONE RIVER

094260801, Hancock, IA

Built 1989 Load: 37.0 t ADT: 50

S RIVERSIDE DR

Good

Over: WILLOW CREEK

079062200, Johnson, IA

Built 1971 Load: 37.0 t ADT: 2,048

IA 64

Good

Over: DRAINAGE DITCH

0.7 mi. E of Jct. US 151, Jones, IA

Built 1979 Load: 37.0 t ADT: 2,790

195TH AVE

Good

Over: STREAM

077183106, Marion, IA

Built 2016 Load: 37.0 t ADT: 155

FM

Good

Over: DRAINAGE DITCH

085462210, Monona, IA

Built 1998 Load: 37.0 t ADT: 1,017

LOCAL

Good

Over: STREAM

088361701, Sac, IA

Built 2001 Load: 37.0 t ADT: 15

LOCAL

Good

Over: WOLF CREEK

070220804, Wayne, IA

Built 1987 Load: 37.0 t ADT: 30

WB US 20

Good

Over: W FK LITTLE SIOUX RIVER

0.1 mi W of jct IA 140, Woodbury, IA

Built 2004 Load: 37.0 t ADT: 4,600

LOCAL

Good

Over: BR BLUE CREEK

086092201, Benton, IA

Built 1988 Load: 37.1 t ADT: 44

LOCAL

Good

Over: SPRING CKEEK

086111602, Benton, IA

Built 1991 Load: 37.1 t ADT: 20

Showing 13,301-13,350 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.