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: BACON CREEK

088420202, Woodbury, IA

Built 1984 Load: 29.8 t ADT: 20

US 69

Fair

Over: DRAINAGE DITCH

2.2 mi N of jct SR C70, Wright, IA

Built 1929 Load: 29.8 t ADT: 2,020

FM

Fair

Over: BEAVER CREEK

083281604, Boone, IA

Built 1973 Load: 29.9 t ADT: 219

LOCAL

Fair

Over: BEAVER CREEK

083281702, Boone, IA

Built 1968 Load: 29.9 t ADT: 30

FM

Fair

Over: BLUFF CREEK

085273202, Boone, IA

Built 1965 Load: 29.9 t ADT: 977

190TH ST

Fair

Over: OVERFLOW

092111901, Bremer, IA

Built 1975 Load: 29.9 t ADT: 727

LOCAL

Fair

Over: SMALL STREAM

090171302, Butler, IA

Built 1990 Load: 29.9 t ADT: 30

JAY AVE.

Fair

Over: COLD WATER CREEK

093171002, Butler, IA

Built 1983 Load: 29.9 t ADT: 51

LOCAL

Fair

Over: PLUM CREEK

096123301, Chickasaw, IA

Built 1996 Load: 29.9 t ADT: 16

FM

Fair

Over: BEE CREEK

071263401, Clarke, IA

Built 1977 Load: 29.9 t ADT: 15

FM

Fair

Over: LONG CREEK

071271403, Clarke, IA

Built 1962 Load: 29.9 t ADT: 71

FM

Fair

Over: EAST BOYER RIVER

084371102, Crawford, IA

Built 1970 Load: 29.9 t ADT: 40

205 AVE

Fair

Over: SPRING CREEK

089053504, Delaware, IA

Built 1975 Load: 29.9 t ADT: 295

205 AVE

Fair

Over: SPRING CREEK

089053504, Delaware, IA

Built 1975 Load: 29.9 t ADT: 295

FM 270 AVE

Fair

Over: PLUM CREEK

089042402, Delaware, IA

Built 1969 Load: 29.9 t ADT: 275

FM 110 AVE

Fair

Over: PRAIRIE CREEK

089062906, Delaware, IA

Built 1986 Load: 29.9 t ADT: 206

FM

Fair

Over: CEDAR FORK

071041201, Des Moines, IA

Built 1964 Load: 29.9 t ADT: 610

FM

Fair

Over: WOLF CREEK

086173404, Grundy, IA

Built 1982 Load: 29.9 t ADT: 1,493

LOCAL

Fair

Over: BR BLACKHAWK CREEK

087170702, Grundy, IA

Built 1979 Load: 29.9 t ADT: 49

LOCAL

Fair

Over: BR BLACKHAWK CREEK

087170903, Grundy, IA

Built 1978 Load: 29.9 t ADT: 88

LOCAL ROAD

Fair

Over: BLACKHAWK CREEK

087181001, Grundy, IA

Built 1977 Load: 29.9 t ADT: 70

FM

Fair

Over: BLACK HAWK CREEK

088150802, Grundy, IA

Built 1974 Load: 29.9 t ADT: 1,404

FM

Fair

Over: BEAVER CREEK

088181503, Grundy, IA

Built 1974 Load: 29.9 t ADT: 265

FM

Fair

Over: BEAVER CREEK ,BRANCH

089182001, Grundy, IA

Built 1971 Load: 29.9 t ADT: 79

LOCAL

Fair

Over: WHITE FOX CR

089250303, Hamilton, IA

Built 1978 Load: 29.9 t ADT: 30

IA 136

Fair

Over: LITTLE BEAR CREEK

0.8 mi. N of Jct. IA 64, Jones, IA

Built 1952 Load: 29.9 t ADT: 930

UNDERWOOD AVE

Fair

Over: CREEK

097150402, Mitchell, IA

Built 1970 Load: 29.9 t ADT: 570

GLASS AVE

Fair

Over: ROCK CREEK

097170702, Mitchell, IA

Built 1977 Load: 29.9 t ADT: 678

FM

Fair

Over: EAST TARKIO CREEK

071372504, Montgomery, IA

Built 1969 Load: 29.9 t ADT: 50

LOCAL

Fair

Over: CREEK

078013101, Muscatine, IA

Built 1955 Load: 29.9 t ADT: 30

LOCAL

Fair

Over: NORTH LIZARD CR(DD#77)

091310902, Pocahontas, IA

Built 1982 Load: 29.9 t ADT: 11

380TH STREET

Fair

Over: STREAM

075402102, Pottawattamie, IA

Built 1953 Load: 29.9 t ADT: 26

LOCAL

Fair

Over: BEAR CREEK

080150202, Poweshiek, IA

Built 1979 Load: 29.9 t ADT: 20

FM

Fair

Over: MIDDLE PLATTE

071310102, Union, IA

Built 1975 Load: 29.9 t ADT: 927

FM

Fair

Over: E BR MIDDLE PLATTE RIVER

071311502, Union, IA

Built 1980 Load: 29.9 t ADT: 20

FM

Fair

Over: EAST PLATTE RIVER

071313402, Union, IA

Built 1983 Load: 29.9 t ADT: 15

FM

Fair

Over: PLATTE RIVER

072311501, Union, IA

Built 1979 Load: 29.9 t ADT: 757

FM

Fair

Over: WOLF CREEK

074220906, Warren, IA

Built 1975 Load: 29.9 t ADT: 887

FM

Fair

Over: SMALL STREAM

076081901, Washington, IA

Built 1953 Load: 29.9 t ADT: 540

WAR EAGLE DRIVE

Fair

Over: B.N. RR

000000000, Woodbury, IA

Built 1995 Load: 29.9 t ADT: 8,703

LOCAL

Fair

Over: DRY CREEK

083091201, Benton, IA

Built 1984 Load: 30.0 t ADT: 44

LOCAL

Fair

Over: HINKLE CREEK

085101902, Benton, IA

Built 1984 Load: 30.0 t ADT: 71

LOCAL

Fair

Over: HINKLE CREEK

085112703, Benton, IA

Built 1973 Load: 30.0 t ADT: 34

E DONALD ST

Fair

Over: ELK RUN CREEK

89-12-15-01-10, Black Hawk, IA

Built 1971 Load: 30.0 t ADT: 1,375

FM

Fair

Over: DES MOINES RIVER

085271403, Boone, IA

Built 1955 Load: 30.0 t ADT: 709

FM W45

Fair

Over: DRY CREEK

087073302, Buchanan, IA

Built 1974 Load: 30.0 t ADT: 717

FM

Fair

Over: W BR PINE CREEK

089080502, Buchanan, IA

Built 1977 Load: 30.0 t ADT: 344

IA 3

Fair

Over: BOYLAN CREEK

2.4 mi. E of jct. SR T16, Butler, IA

Built 1927 Load: 30.0 t ADT: 1,080

FM

Fair

Over: WEST NISHNABOTNA RIVER

082363101, Carroll, IA

Built 1970 Load: 30.0 t ADT: 120

300TH ST

Fair

Over: E BR WAPSINONOC CR

079031701, Cedar, IA

Built 2006 Load: 30.0 t ADT: 34

Showing 5,401-5,450 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.