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

Poor

Over: OTTER CREEK

083142905, Tama, IA

Built 1930 Load: 18.8 t ADT: 29

LOCAL

Poor

Over: CREEK

068080204, Van Buren, IA

Built 1969 Load: 18.8 t ADT: 51

FM

Poor

Over: CREEK

068111810, Van Buren, IA

Built 1955 Load: 18.8 t ADT: 25

LOCAL

Poor

Over: CREEK

070110707, Van Buren, IA

Built 1956 Load: 18.8 t ADT: 50

LOCAL

Poor

Over: STREAM

069161005, Appanoose, IA

Built 1900 Load: 18.9 t ADT: 21

LOCAL

Poor

Over: DD 37

089341102, Calhoun, IA

Built 1960 Load: 18.9 t ADT: 26

LOCAL - 760TH

Poor

Over: WEST NODAWAY CREEK

075343504, Cass, IA

Built 1988 Load: 18.9 t ADT: 11

330TH ST

Poor

Over: STREAM

079043501, Cedar, IA

Built 1930 Load: 18.9 t ADT: 11

LOCAL

Poor

Over: CREEK

097133402, Chickasaw, IA

Built 1970 Load: 18.9 t ADT: 35

FM

Poor

Over: WEST CREEK

073251604, Clarke, IA

Built 1958 Load: 18.9 t ADT: 459

LOCAL

Poor

Over: STREAM

094313601, Palo Alto, IA

Built 1927 Load: 18.9 t ADT: 90

LOCAL

Poor

Over: SMALL STREAM

089082804, Buchanan, IA

Built 1951 Load: 19.0 t ADT: 15

LOCAL

Poor

Over: FIELD STREAM

083363002, Carroll, IA

Built 1962 Load: 19.0 t ADT: 11

255TH ST

Poor

Over: CROOKED CREEK

080021905, Cedar, IA

Built 1965 Load: 19.0 t ADT: 40

FM

Poor

Over: BEAR CREEK

079311802, Guthrie, IA

Built 1959 Load: 19.0 t ADT: 120

LOCAL

Poor

Over: ODEBOLT CREEK

087402403, Ida, IA

Built 1967 Load: 19.0 t ADT: 2,884

FM

Poor

Over: OVERFLOW

098430501, Lyon, IA

Built 1969 Load: 19.0 t ADT: 718

LOCAL

Poor

Over: CREEK

085171902, Marshall, IA

Built 1940 Load: 19.0 t ADT: 30

LOCAL

Poor

Over: STREAM

100411403, Osceola, IA

Built 1957 Load: 19.0 t ADT: 41

FM C-43

Poor

Over: BROKEN KETTLE CREEK

091482205, Plymouth, IA

Built 1960 Load: 19.0 t ADT: 159

LOCAL

Poor

Over: LIZARD CREEK DD #164

091313102, Pocahontas, IA

Built 1978 Load: 19.0 t ADT: 30

LOCAL

Poor

Over: SMALL

079161701, Poweshiek, IA

Built 1979 Load: 19.0 t ADT: 90

650TH AVE

Poor

Over: EAST BR INDIAN CREEK

085222702, Story, IA

Built 1922 Load: 19.0 t ADT: 60

140TH ST

Poor

Over: EAST BR INDIAN CREEK

085222901, Story, IA

Built 1924 Load: 19.0 t ADT: 5

520TH AVE

Poor

Over: KEIGLEY BRANCH

085240902, Story, IA

Built 1949 Load: 19.0 t ADT: 34

LOCAL

Poor

Over: WOLF CREEK

087441101, Woodbury, IA

Built 1981 Load: 19.0 t ADT: 20

E35 (200TH ST)

Poor

Over: FIELD STREAM

084363001, Carroll, IA

Built 1946 Load: 19.1 t ADT: 60

1970 CRANE AVE

Poor

Over: DD #10

095261602, Hancock, IA

Built 1969 Load: 19.1 t ADT: 15

FM

Poor

Over: MAQUOKETA RIVER

084E40803, Jackson, IA

Built 1950 Load: 19.1 t ADT: 330

LOCAL

Poor

Over: NORTH SKUNK RIVER

080182601, Jasper, IA

Built 1918 Load: 19.1 t ADT: 25

FM

Poor

Over: SNIPE CREEK

081191503, Jasper, IA

Built 1927 Load: 19.1 t ADT: 90

EBYS MILL RD

Poor

Over: SMALL CREEK

085020203, Jones, IA

Built 1964 Load: 19.1 t ADT: 44

LOCAL SECONDARY

Poor

Over: SUGAR CREEK

069073201, Lee, IA

Built 1976 Load: 19.1 t ADT: 15

FM

Poor

Over: RIGGS CREEK

100471204, Lyon, IA

Built 1970 Load: 19.1 t ADT: 290

LOCAL

Poor

Over: BRANCH N SKUNK RIVER

082203602, Marshall, IA

Built 1940 Load: 19.1 t ADT: 26

LOCAL

Poor

Over: CREEK

085183106, Marshall, IA

Built 1939 Load: 19.1 t ADT: 62

LOCAL

Poor

Over: WALNUT CREEK

081152302, Poweshiek, IA

Built 1926 Load: 19.1 t ADT: 5

640TH AVE

Poor

Over: CALAMUS CREEK

082222804, Story, IA

Built 1938 Load: 19.1 t ADT: 45

LOCAL

Poor

Over: EAST BRANCH SALT CREEK

085133401, Tama, IA

Built 1969 Load: 19.1 t ADT: 39

BIRCH RD.

Poor

Over: DIBBLE CREEK

095071105, Fayette, IA

Built 1917 Load: 19.2 t ADT: 20

FM

Poor

Over: SOUTH RACCOON

080331210, Guthrie, IA

Built 1957 Load: 19.2 t ADT: 26

LOCAL

Poor

Over: STREAM

081300701, Guthrie, IA

Built 1928 Load: 19.2 t ADT: 15

LOCAL

Poor

Over: SMALL STREAM

080201101, Jasper, IA

Built 1929 Load: 19.2 t ADT: 41

LOCAL

Poor

Over: STREAM

076140602, Mahaska, IA

Built 1953 Load: 19.2 t ADT: 45

LOCAL

Poor

Over: MUD CREEK

077220201, Polk, IA

Built 1920 Load: 19.2 t ADT: 50

LOCAL

Poor

Over: TWELVE MILE CREEK

086151002, Tama, IA

Built 1925 Load: 19.2 t ADT: 39

185TH ST.

Poor

Over: STREAM

092161703, Butler, IA

Built 1900 Load: 19.3 t ADT: 35

LOCAL

Poor

Over: CAMP CR.

087340503, Calhoun, IA

Built 1900 Load: 19.3 t ADT: 20

LOCAL

Poor

Over: DD

089223101, Hardin, IA

Built 1900 Load: 19.3 t ADT: 41

LOC CRESCENT AV

Poor

Over: BR LITTLE WAPSIPINICON R

098140904, Howard, IA

Built 1970 Load: 19.3 t ADT: 42

Showing 17,901-17,950 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.