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

LOC 400TH ST

Good

Over: MAQUOKETA RIVER

090060501, Delaware, IA

Built 1986 Load: 36.0 t ADT: 157

ACORN RD

Good

Over: VOLGA RIVER

093072506, Fayette, IA

Built 2019 Load: 36.0 t ADT: 39

FM

Good

Over: OVER IMRL RR

095160216, Floyd, IA

Built 2008 Load: 36.0 t ADT: 3,339

LARK AVE

Good

Over: DRAINAGE DITCH NO 55

93212502, Franklin, IA

Built 2017 Load: 36.0 t ADT: 43

270TH ST

Good

Over: CREEK

091283203, Humboldt, IA

Built 2017 Load: 36.0 t ADT: 30

D22 165TH ST

Good

Over: BACON CREEK

088410605, Ida, IA

Built 2021 Load: 36.0 t ADT: 319

FM 3 CO BR RD

Good

Over: BR PRAIRIE CREEK

077053103, Johnson, IA

Built 1997 Load: 36.0 t ADT: 80

SW SIOUX AVE

Good

Over: STREAM

078051902, Johnson, IA

Built 1966 Load: 36.0 t ADT: 50

FM UTAH AVE

Good

Over: STREAM

078052702, Johnson, IA

Built 1998 Load: 36.0 t ADT: 2,020

NAPLES AVE SW

Good

Over: OLD MAN'S CREEK

078060504, Johnson, IA

Built 1985 Load: 36.0 t ADT: 11

LOCAL

Good

Over: SMALL STREAM

078060702, Johnson, IA

Built 1997 Load: 36.0 t ADT: 30

LOCAL

Good

Over: DIRTY FACE CREEK

078071702, Johnson, IA

Built 1997 Load: 36.0 t ADT: 40

560TH ST SW

Good

Over: STREAM

078083601, Johnson, IA

Built 1900 Load: 36.0 t ADT: 51

OSAGE RD

Good

Over: SMALL STREAM

079052502, Johnson, IA

Built 1989 Load: 36.0 t ADT: 40

KANSAS AVE

Good

Over: DEER CREEK

079070202, Johnson, IA

Built 1994 Load: 36.0 t ADT: 140

IRELAND AVE

Good

Over: DEER CR

079070404, Johnson, IA

Built 2005 Load: 36.0 t ADT: 120

FM SW IVY AVE

Good

Over: OLD WOMEN'S CR

079071602, Johnson, IA

Built 1977 Load: 36.0 t ADT: 100

FM IWV RD

Good

Over: OLD WOMEN'S CR

079071701, Johnson, IA

Built 2006 Load: 36.0 t ADT: 1,020

FM ROHRET RD

Good

Over: OLD WOMENS CR

079072801, Johnson, IA

Built 2004 Load: 36.0 t ADT: 60

FM SW BLK HWK D

Good

Over: N BR OLD MAN'S CR

079080508, Johnson, IA

Built 2000 Load: 36.0 t ADT: 1,450

NAPLES AVE

Good

Over: HOOSIER CR

081060504, Johnson, IA

Built 2000 Load: 36.0 t ADT: 39

RACINE AVE

Good

Over: STREAM

081062502, Johnson, IA

Built 2002 Load: 36.0 t ADT: 181

CALKINS AVE

Good

Over: KNAPP CR

081080402, Johnson, IA

Built 2008 Load: 36.0 t ADT: 49

LOCAL

Good

Over: SMALL STREAM

077052101, Johnson, IA

Built 1999 Load: 36.0 t ADT: 60

IA 64

Good

Over: DRAINAGE DITCH

1.4 MI. W OF JCT. IA 136, Jones, IA

Built 1979 Load: 36.0 t ADT: 1,720

CENTRAL PARK RD

Good

Over: MINERAL CREEK

084020606, Jones, IA

Built 2015 Load: 36.0 t ADT: 90

CEDAR RIVER RD.

Good

Over: BALES BRANCH CR.

082051802, Linn, IA

Built 1983 Load: 36.0 t ADT: 1,738

SPRING CR.RD.

Good

Over: SPRING CREEK

082052806, Linn, IA

Built 1992 Load: 36.0 t ADT: 97

ELY RD

Good

Over: PLEASANT RUN CREEK

082071306, Linn, IA

Built 1958 Load: 36.0 t ADT: 5,008

SPRINGVILLE RD

Good

Over: ELBOW CREEK

083051602, Linn, IA

Built 1960 Load: 36.0 t ADT: 687

ELLIS RD

Good

Over: SILVER CREEK

083081605, Linn, IA

Built 1990 Load: 36.0 t ADT: 707

LOCAL

Good

Over: SILVER CREEK

083081704, Linn, IA

Built 1991 Load: 36.0 t ADT: 108

HODGIN RD

Good

Over: TRIB E BIG CREEK

084052101, Linn, IA

Built 1986 Load: 36.0 t ADT: 49

TOWER TER.RD.

Good

Over: TRIB. OTTER CREEK

084082417, Linn, IA

Built 1985 Load: 36.0 t ADT: 1,777

WAUBEEK RD

Good

Over: RICOCHET CREEK

085062405, Linn, IA

Built 2001 Load: 36.0 t ADT: 373

E OTTER RD

Good

Over: EAST OTTER CREEK

085072809, Linn, IA

Built 1978 Load: 36.0 t ADT: 108

HAZEL ST

Good

Over: KEG CREEK

000000000, Mills, IA

Built 2009 Load: 36.0 t ADT: 1,704

135TH ST

Good

Over: BRANCH OF MUD CREEK

078E12203, Muscatine, IA

Built 2023 Load: 36.0 t ADT: 91

US 75

Good

Over: STREAM

0.1 mi. N of SR C70, Plymouth, IA

Built 2019 Load: 36.0 t ADT: 14,900

US 75

Good

Over: STREAM

0.3 mi N of SR C70, Plymouth, IA

Built 2019 Load: 36.0 t ADT: 14,900

US 75

Good

Over: STREAM

0.7 mi N of SR C70, Plymouth, IA

Built 2019 Load: 36.0 t ADT: 14,900

US 75

Good

Over: STREAM

1.5 mi. S of SR C60, Plymouth, IA

Built 2019 Load: 36.0 t ADT: 14,900

I 35

Good

Over: OTTER CREEK

1.8 MI. S OF NE 126TH AVE, Polk, IA

Built 2012 Load: 36.0 t ADT: 47,500

SE 20TH AVE

Good

Over: BRANCH MUD CREEK

078221603, Polk, IA

Built 2013 Load: 36.0 t ADT: 60

NE 24TH COURT

Good

Over: FOUR MILE CREEK

NE 24th Ct over 4 Mile Cr, Polk, IA

Built 2017 Load: 36.0 t ADT: 150

ROLLAND AVE

Good

Over: OUTLET CREEK

087363602, Sac, IA

Built 2022 Load: 36.0 t ADT: 20

140TH AVE

Good

Over: CREEK

079E30402, Scott, IA

Built 2019 Load: 36.0 t ADT: 50

KIMBERLY RD

Good

Over: DUCK CREEK

000000000, Scott, IA

Built 1963 Load: 36.0 t ADT: 10,500

FM

Good

Over: SMALL

094433501, Sioux, IA

Built 1983 Load: 36.0 t ADT: 41

LOCAL

Good

Over: SMALL STREAM

094451902, Sioux, IA

Built 1984 Load: 36.0 t ADT: 34

Showing 13,051-13,100 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.