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: W FORK NISHNABOTNA RIVER

083372202, Crawford, IA

Built 2004 Load: 30.1 t ADT: 30

WB US 34

Fair

Over: BNSF RR

0.3 mi. W of jct. US 61, Des Moines, IA

Built 1976 Load: 30.1 t ADT: 4,250

NB NW ARTERIAL

Fair

Over: OVER CC RR & CATFISH CK

0.2 MI. N OF JCT. US 20, Dubuque, IA

Built 1982 Load: 30.1 t ADT: 5,295

LOCAL

Fair

Over: CREEK D D 94

098332903, Emmet, IA

Built 1975 Load: 30.1 t ADT: 34

GREAT RIVER RD.

Fair

Over: TURKEY RIVER

095073007, Fayette, IA

Built 1978 Load: 30.1 t ADT: 314

50TH ST

Fair

Over: SMALL STREAM

084E71903, Jackson, IA

Built 1986 Load: 30.1 t ADT: 40

FM

Fair

Over: FARMERS CREEK

086E32003, Jackson, IA

Built 1979 Load: 30.1 t ADT: 570

FM

Fair

Over: SMALL STREAM

084E51506, Jackson, IA

Built 1996 Load: 30.1 t ADT: 45

190TH ST

Fair

Over: BRANCH KITTY CREEK

085030203, Jones, IA

Built 1959 Load: 30.1 t ADT: 137

FM

Fair

Over: LOST CREEK

068041202, Lee, IA

Built 1970 Load: 30.1 t ADT: 360

NB I-380

Fair

Over: OVER UP RR

1.0 MI. N OF JCT. US 30, Linn, IA

Built 1974 Load: 30.1 t ADT: 31,400

IA 175

Fair

Over: MUCKY CREEK

0.8 mi. W of W Jct IA 141, Monona, IA

Built 1973 Load: 30.1 t ADT: 1,200

LOCAL

Fair

Over: OTTER CREEK

099413002, Osceola, IA

Built 1940 Load: 30.1 t ADT: 81

FM

Fair

Over: MC CARTY CREEK

079E52702, Scott, IA

Built 1992 Load: 30.1 t ADT: 100

LOCAL

Fair

Over: W FORK FLOYD RIV

095453303, Sioux, IA

Built 1969 Load: 30.1 t ADT: 131

FM

Fair

Over: BURR OAK CREEK

097451402, Sioux, IA

Built 1967 Load: 30.1 t ADT: 1,097

LOCAL

Fair

Over: W WOLFE CREEK

073282003, Union, IA

Built 1995 Load: 30.1 t ADT: 46

LOCAL

Fair

Over: CREEK

0.1 Mi W Jct 205th Rd, Van Buren, IA

Built 2010 Load: 30.1 t ADT: 35

WILDWOOD DR

Fair

Over: CHNG.CHL.BEAR CK(SDB)

1.4 mi. W of Jct. IA 149, Wapello, IA

Built 1963 Load: 30.1 t ADT: 10

LOCAL

Fair

Over: SHOAL CREEK

068181906, Appanoose, IA

Built 1979 Load: 30.2 t ADT: 41

LOCAL

Fair

Over: PRAIRIE CK

083111902, Benton, IA

Built 1975 Load: 30.2 t ADT: 15

LOCAL

Fair

Over: LITTLE BEAR CREEK

084093401, Benton, IA

Built 1985 Load: 30.2 t ADT: 49

LOCAL

Fair

Over: WILDCAT CREEK

084103402, Benton, IA

Built 1984 Load: 30.2 t ADT: 20

LOCAL

Fair

Over: PRATT CREEK

086113301, Benton, IA

Built 1984 Load: 30.2 t ADT: 20

LOCAL

Fair

Over: PRARIE CREEK

086090502, Benton, IA

Built 2002 Load: 30.2 t ADT: 33

FM

Fair

Over: W BR BUFFALO CREEK

090080807, Buchanan, IA

Built 1974 Load: 30.2 t ADT: 334

LOCAL

Fair

Over: LAKE CREEK

087320803, Calhoun, IA

Built 1974 Load: 30.2 t ADT: 11

LOCAL

Fair

Over: D D 181

089340901, Calhoun, IA

Built 1979 Load: 30.2 t ADT: 26

FM

Fair

Over: MIDDLE RACCOON RIVER

083342305, Carroll, IA

Built 1982 Load: 30.2 t ADT: 50

FM

Fair

Over: SUGAR CREEK

080022803, Cedar, IA

Built 1960 Load: 30.2 t ADT: 50

LOCAL

Fair

Over: NORTH WHITE BREAST CREEK

071240504, Clarke, IA

Built 1982 Load: 30.2 t ADT: 60

FM

Fair

Over: CHARITON CREEK

071242302, Clarke, IA

Built 1980 Load: 30.2 t ADT: 50

FM

Fair

Over: NO WHITE BREAST CREEK

072253604, Clarke, IA

Built 1981 Load: 30.2 t ADT: 50

FM

Fair

Over: OTTER CREEK

073240104, Clarke, IA

Built 1980 Load: 30.2 t ADT: 71

FM 160TH AVE

Fair

Over: OCHEYEDAN RIVER

096370702, Clay, IA

Built 1981 Load: 30.2 t ADT: 40

FM

Fair

Over: W FK W NISHNABOTNA RIVER

082370601, Crawford, IA

Built 1975 Load: 30.2 t ADT: 180

FM

Fair

Over: BEAVER CREEK

081281103, Dallas, IA

Built 1979 Load: 30.2 t ADT: 210

FM 315TH ST

Fair

Over: LIME CREEK

087042008, Delaware, IA

Built 1978 Load: 30.2 t ADT: 530

LOCAL

Fair

Over: BUCK CREEK

087051602, Delaware, IA

Built 1983 Load: 30.2 t ADT: 70

EB US 20

Fair

Over: OVER CC RR

0.9 MI. E OF JCT. IA 13, Delaware, IA

Built 1971 Load: 30.2 t ADT: 3,850

FM OLIVE AVE

Fair

Over: OTTER CREEK

092200402, Franklin, IA

Built 1975 Load: 30.2 t ADT: 638

LOCAL

Fair

Over: BR BLACKHAWK CREEK

087170202, Grundy, IA

Built 1979 Load: 30.2 t ADT: 59

LOCAL

Fair

Over: SOUTH BEAVER CREEK

078310509, Guthrie, IA

Built 1983 Load: 30.2 t ADT: 29

FM

Fair

Over: SOUTH FORK MIDDLE RIVER

078323202, Guthrie, IA

Built 1977 Load: 30.2 t ADT: 79

LOCAL

Fair

Over: MIDDLE RIVER

078330106, Guthrie, IA

Built 1982 Load: 30.2 t ADT: 29

LOCAL

Fair

Over: STREAM

079300901, Guthrie, IA

Built 1979 Load: 30.2 t ADT: 71

FM

Fair

Over: SOUTH RACCOON

080322001, Guthrie, IA

Built 1972 Load: 30.2 t ADT: 259

LOCAL

Fair

Over: MOSQUITO CREEK

081301701, Guthrie, IA

Built 1981 Load: 30.2 t ADT: 34

LOCAL

Fair

Over: MOSQUITO CREEK

081302801, Guthrie, IA

Built 1983 Load: 30.2 t ADT: 29

FM

Fair

Over: WILLOW CREEK

081322301, Guthrie, IA

Built 1985 Load: 30.2 t ADT: 71

Showing 5,501-5,550 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.