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

ZELLER STREET

Fair

Over: MUDDY CREEK

West of Crandic RR, Johnson, IA

Built 1999 Load: 34.7 t ADT: 4,290

COUNTY RD E-45

Fair

Over: SMALL CREEK

083010707, Jones, IA

Built 1980 Load: 34.7 t ADT: 422

120TH AVE

Fair

Over: SMALL CREEK

083022902, Jones, IA

Built 1980 Load: 34.7 t ADT: 16

60TH AVE.

Fair

Over: SMALL CREEK

084011904, Jones, IA

Built 2007 Load: 34.7 t ADT: 123

BOYSCOUTS RD

Fair

Over: WAPSIPINICON RIVER

085052003, Linn, IA

Built 1976 Load: 34.7 t ADT: 226

FM

Fair

Over: SKUNK RIVER

077180304, Marion, IA

Built 1948 Load: 34.7 t ADT: 1,300

Co. Highway

Fair

Over: Des Moines River

Red Rock Dam, Marion, IA

Built 1967 Load: 34.7 t ADT: 3,750

FM

Fair

Over: DRY RUN

076040303, Muscatine, IA

Built 1986 Load: 34.7 t ADT: 550

LOCAL

Fair

Over: SMALL STREAM

087361801, Sac, IA

Built 1985 Load: 34.7 t ADT: 15

PK 607(BLKHAWK)

Fair

Over: BLACK HAWK LAKE

Black Hawk Lake St. Park, Sac, IA

Built 1989 Load: 34.7 t

K64

Fair

Over: UNNAMED CREEK

095440402, Sioux, IA

Built 1900 Load: 34.7 t ADT: 1,117

BIRCH AVE

Fair

Over: BIG SIOUX RIVER

097481404, Sioux, IA

Built 1966 Load: 34.7 t ADT: 450

MINNESOTA AVE

Fair

Over: OVER UPRR

A66600500, Story, IA

Built 1980 Load: 34.7 t ADT: 488

FM

Fair

Over: MIDDLE BRANCH 102 RIVER

070332103, Taylor, IA

Built 1983 Load: 34.7 t ADT: 390

LOCAL

Fair

Over: CREEK

069100904, Van Buren, IA

Built 1980 Load: 34.7 t ADT: 62

IA 92

Fair

Over: SOUTH RIVER

0.4 MI E OF E JCT SR S23, Warren, IA

Built 1983 Load: 34.7 t ADT: 2,190

FM

Fair

Over: UPPER IOWA RIVER

098070705, Winneshiek, IA

Built 1967 Load: 34.7 t ADT: 265

LOCAL RD

Fair

Over: SMALL STREAM

077311401, Adair, IA

Built 2004 Load: 34.8 t ADT: 15

LOCAL

Fair

Over: CREEK

078351607, Audubon, IA

Built 1924 Load: 34.8 t ADT: 15

SIDE ROAD

Fair

Over: DRAINAGE

Fairgrounds, Audubon, IA

Built 1938 Load: 34.8 t

NB I-35

Fair

Over: WHITE BREAST CREEK

1.3 MI. S OF JCT. US 34, Clarke, IA

Built 1969 Load: 34.8 t ADT: 8,650

JORDAN CR PKWY

Fair

Over: CREEK

000000000, Dallas, IA

Built 2003 Load: 34.8 t ADT: 14,127

EB I-80

Fair

Over: OVER IAIS RR

0.4 MILES W OF JCT IA 14, Jasper, IA

Built 1962 Load: 34.8 t ADT: 16,700

FM

Fair

Over: KEEVERS LAKE

073020803, Louisa, IA

Built 1988 Load: 34.8 t ADT: 70

SB I-29

Fair

Over: BNSF RR & EATON DITCH

0.8 MI N OF S JCT. US 34, Mills, IA

Built 1970 Load: 34.8 t ADT: 6,800

LOCAL

Fair

Over: DRAINAGE

071381302, Montgomery, IA

Built 1992 Load: 34.8 t ADT: 45

FM

Fair

Over: STREAM

081142101, Poweshiek, IA

Built 1962 Load: 34.8 t ADT: 20

FM

Fair

Over: LITTLE SIOUX RIVER

088433305, Woodbury, IA

Built 1992 Load: 34.8 t ADT: 679

LOCAL ROAD

Fair

Over: FORK OF RATHBUN LAKE

070192214, Appanoose, IA

Built 1968 Load: 34.9 t ADT: 440

IA 150

Fair

Over: STREAM

0.1 MI. S OF JCT. I-380, Benton, IA

Built 1981 Load: 34.9 t ADT: 1,230

LOCAL

Fair

Over: S. WHITEBREAST CREEK

071251006, Clarke, IA

Built 1996 Load: 34.9 t ADT: 26

WB US 30

Fair

Over: AMES CREEK

3.5 MI E OF E JCT US 61, Clinton, IA

Built 1974 Load: 34.9 t ADT: 4,700

LOCAL

Fair

Over: SMALL STREAM

084400901, Crawford, IA

Built 1900 Load: 34.9 t ADT: 11

EB IA 141

Fair

Over: FROG CREEK

0.1 MILE W OF JCT IA 144, Dallas, IA

Built 1976 Load: 34.9 t ADT: 2,210

FM

Fair

Over: SOAP CREEK

070120204, Davis, IA

Built 1979 Load: 34.9 t ADT: 140

IA 175

Fair

Over: MOREHEAD CREEK

2.6 mi. W of W jct SR L51, Ida, IA

Built 1985 Load: 34.9 t ADT: 940

HOLIDAY RD

Fair

Over: OVER CIC RR

000000000, Johnson, IA

Built 1979 Load: 34.9 t ADT: 5,126

LOC 30TH AVE

Fair

Over: E FORK DES MOINES RIVER

098300904, Kossuth, IA

Built 1992 Load: 34.9 t ADT: 35

US 34

Fair

Over: LITTLE WHITE BREAST CK

2.5 MI. W OF Jct. SR S56, Lucas, IA

Built 1958 Load: 34.9 t ADT: 3,080

FM

Fair

Over: TURNER CREEK

100442201, Lyon, IA

Built 1980 Load: 34.9 t ADT: 71

FA-BROTHERS AVE

Fair

Over: BOX ELDER CREEK

073411103, Mills, IA

Built 1985 Load: 34.9 t ADT: 131

LOCAL

Fair

Over: JACK CREEK

097331104, Palo Alto, IA

Built 1986 Load: 34.9 t ADT: 73

20TH ST

Fair

Over: SOAP CREEK

071132902, Wapello, IA

Built 1990 Load: 34.9 t ADT: 50

LOCAL

Fair

Over: STREAM

086272106, Webster, IA

Built 1997 Load: 34.9 t ADT: 30

210TH STREET

Fair

Over: STREAM

072333601, Adams, IA

Built 1971 Load: 35.0 t ADT: 11

LOCAL

Fair

Over: YELLOW RIVER

096060506, Allamakee, IA

Built 1993 Load: 35.0 t ADT: 49

LOCAL

Fair

Over: SMALL STREAM

088081502, Buchanan, IA

Built 1940 Load: 35.0 t ADT: 35

FM 580TH ST.

Fair

Over: LITTLE SIOUX RIVER

091402801, Cherokee, IA

Built 1981 Load: 35.0 t ADT: 350

FM 170TH AVE

Fair

Over: WILLOW CREEK

095373202, Clay, IA

Built 1963 Load: 35.0 t ADT: 219

FETTKETHER LANE

Fair

Over: NO FORK LITTLE MAQUOKETA

090E12812, Dubuque, IA

Built 2017 Load: 35.0 t ADT: 20

Showing 7,501-7,550 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.