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

Fair

Over: SMALL

071273303, Clarke, IA

Built 1979 Load: 29.3 t ADT: 26

FM

Fair

Over: N WYACONDAH RIVER

068123202, Davis, IA

Built 1970 Load: 29.3 t ADT: 210

GREAT RIVER RD.

Fair

Over: TURKEY RIVER

095080805, Fayette, IA

Built 1979 Load: 29.3 t ADT: 177

LOCAL

Fair

Over: BLACKHAWK CREEK

088161302, Grundy, IA

Built 1957 Load: 29.3 t ADT: 26

FM

Fair

Over: FROST CREEK

080321901, Guthrie, IA

Built 1974 Load: 29.3 t ADT: 259

HIGHWAY F-48 W

Fair

Over: OVER IAIS RR

079200503, Jasper, IA

Built 1977 Load: 29.3 t ADT: 1,470

95TH AVE

Fair

Over: BRANCH OF MINERAL CREEK

085022206, Jones, IA

Built 1953 Load: 29.3 t ADT: 20

175TH ST.

Fair

Over: KITTY CREEK

085030817, Jones, IA

Built 1983 Load: 29.3 t ADT: 35

FM

Fair

Over: ALLEN CREEK

098443601, Lyon, IA

Built 1978 Load: 29.3 t ADT: 45

FM

Fair

Over: ARGO SLOUGH

099431002, Lyon, IA

Built 1980 Load: 29.3 t ADT: 45

LOCAL ROAD

Fair

Over: SPRING CREEK

099461701, Lyon, IA

Built 1981 Load: 29.3 t ADT: 30

FM

Fair

Over: BIG SIOUX RIVER

90948, Plymouth, IA

Built 1967 Load: 29.3 t ADT: 589

US 275 & IA 92

Fair

Over: OVER BNSF RR/SM STREAM

0.4 MI. N OF N Jct I-29, Pottawattamie, IA

Built 1968 Load: 29.3 t ADT: 5,050

LOCAL

Fair

Over: STREAM

079160101, Poweshiek, IA

Built 1968 Load: 29.3 t ADT: 30

LOCAL ROAD

Fair

Over: TURKEY RIVER

098102801, Winneshiek, IA

Built 1962 Load: 29.3 t ADT: 39

E WAHSBURN RD

Fair

Over: CEDAR RIVER

88-12-22-07, Black Hawk, IA

Built 1958 Load: 29.4 t ADT: 1,571

EB US 30

Fair

Over: BROPHYS CREEK

8.5 MI. E OF E JCT. US 61, Clinton, IA

Built 1969 Load: 29.4 t ADT: 5,000

225TH ST.

Fair

Over: SMALL STREAM

081E10303, Clinton, IA

Built 1994 Load: 29.4 t ADT: 26

135TH STREET

Fair

Over: SMALL STREAM

083E52003, Clinton, IA

Built 1984 Load: 29.4 t ADT: 35

FM

Fair

Over: WALNUT CREEK

079260902, Dallas, IA

Built 1969 Load: 29.4 t ADT: 1,246

215 STREET

Fair

Over: SPRING BRANCH

069413303, Fremont, IA

Built 1984 Load: 29.4 t ADT: 46

FM 1400 310TH

Fair

Over: DRAINAGE DITCH 1&2

097242001, Hancock, IA

Built 1974 Load: 29.4 t ADT: 478

SW CALKINS AVE

Fair

Over: N BR CREEK

079080902, Johnson, IA

Built 1920 Load: 29.4 t ADT: 26

FM SW BLK DIMND

Fair

Over: STREAM

079083405, Johnson, IA

Built 1900 Load: 29.4 t ADT: 970

GLASS RD

Fair

Over: OVER CC RR & MCCLOUD RUN

000000000, Linn, IA

Built 1980 Load: 29.4 t ADT: 5,700

IA 48

Fair

Over: EAST NISHNABOTNA RIVER

1.9 MI. S OF SR H14, Montgomery, IA

Built 1960 Load: 29.4 t ADT: 1,210

LOCAL

Fair

Over: SMALL STREAM

073363006, Montgomery, IA

Built 1987 Load: 29.4 t ADT: 5

IA 906 EB

Fair

Over: MOSQUITO CREEK

1.0 mi. W of Jct. I-80, Pottawattamie, IA

Built 1968 Load: 29.4 t ADT: 3,900

LOCAL

Fair

Over: BOYER RIVER

089371002, Sac, IA

Built 1978 Load: 29.4 t ADT: 5

FM RD F16

Fair

Over: MOSER CREEK

081392004, Shelby, IA

Built 1981 Load: 29.4 t ADT: 159

190TH ST/E29

Fair

Over: DYE CREEK

084212001, Story, IA

Built 1973 Load: 29.4 t ADT: 669

FM

Fair

Over: NORTH AVERY CREEK

073152604, Wapello, IA

Built 1981 Load: 29.4 t ADT: 470

LOCAL

Fair

Over: VILLAGE CREEK

098041410, Allamakee, IA

Built 1952 Load: 29.5 t ADT: 33

FM

Fair

Over: STREAM

068172604, Appanoose, IA

Built 1987 Load: 29.5 t ADT: 25

LOCAL FROST AVE

Fair

Over: SMALL STREAM

087102304, Buchanan, IA

Built 1976 Load: 29.5 t ADT: 39

FM DENISON AVE

Fair

Over: SMALL CREEK

090101501, Buchanan, IA

Built 1998 Load: 29.5 t ADT: 1,650

CHARLES AVE

Fair

Over: CLEAR CREEK

082042104, Cedar, IA

Built 2005 Load: 29.5 t ADT: 70

470TH ST

Fair

Over: MONTGOMERY CREEK

094361403, Clay, IA

Built 1998 Load: 29.5 t ADT: 30

ESSEX AVE

Fair

Over: STREAM

095050304, Clayton, IA

Built 1910 Load: 29.5 t ADT: 73

IA 141

Fair

Over: DRAINAGE

0.3 MILE W OF JCT. IA 17, Dallas, IA

Built 1973 Load: 29.5 t ADT: 11,100

LOCAL

Fair

Over: CREEK

086220103, Hardin, IA

Built 1989 Load: 29.5 t ADT: 51

LOCAL 95TH ST

Fair

Over: DRAINAGE DITCH

099141903, Howard, IA

Built 1992 Load: 29.5 t ADT: 79

FM

Fair

Over: HOSKINS CREEK

087392702, Ida, IA

Built 2005 Load: 29.5 t ADT: 60

LOCAL

Fair

Over: CREEK

084E10208, Jackson, IA

Built 2003 Load: 29.5 t ADT: 11

LOCAL

Fair

Over: CREEK

084E53402, Jackson, IA

Built 1991 Load: 29.5 t ADT: 99

LOCAL RD

Fair

Over: SMALL CREEK

087E42403, Jackson, IA

Built 1981 Load: 29.5 t ADT: 239

LANGWORTHY RD

Fair

Over: KITTY CREEK

085030818, Jones, IA

Built 1960 Load: 29.5 t ADT: 147

130TH ST

Fair

Over: BRANCH OF MINERAL CREEK

085013203, Jones, IA

Built 1956 Load: 29.5 t ADT: 30

FM

Fair

Over: SUGAR CREEK

068070301, Lee, IA

Built 1963 Load: 29.5 t ADT: 920

IA 140

Fair

Over: RATHBURN CREEK

3.3 mi S of SR C38, Plymouth, IA

Built 1964 Load: 29.5 t ADT: 970

Showing 5,251-5,300 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.