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

I-480 & US 6

Fair

Over: MISSOURI RIVER & RR

OVER MISSOURI RIVER, Pottawattamie, IA

Built 1966 Load: 15.4 t ADT: 53,700

LOCAL

Fair

Over: W. NISHNABOTNA RIVER

081370303, Shelby, IA

Built 1955 Load: 15.4 t ADT: 26

730TH AVE

Fair

Over: CLEAR CREEK

083212402, Story, IA

Built 1931 Load: 15.4 t ADT: 40

LOCAL

Fair

Over: BRUSHY FORK CREEK

082341703, Carroll, IA

Built 1971 Load: 15.5 t ADT: 15

LOCAL

Fair

Over: EAST LONG CREEK

071272603, Clarke, IA

Built 1977 Load: 15.5 t ADT: 5

145TH ST

Fair

Over: ROBERTS CREEK

095062605, Clayton, IA

Built 1953 Load: 15.5 t ADT: 59

FM

Fair

Over: STREAM

068262601, Decatur, IA

Built 1968 Load: 15.5 t ADT: 20

E 124TH ST S

Fair

Over: SMALL STREAM

079170904, Jasper, IA

Built 1988 Load: 15.5 t ADT: 11

LOCAL

Fair

Over: CEDAR CREEK

076260908, Madison, IA

Built 1958 Load: 15.5 t ADT: 34

LOCAL

Fair

Over: OCHEYEDAN RIVER

099400502, Osceola, IA

Built 1954 Load: 15.5 t ADT: 21

250TH ST

Fair

Over: DRAINAGE

091472103, Plymouth, IA

Built 1978 Load: 15.5 t ADT: 15

190TH ST

Fair

Over: WESTFIELD CREEK

092492404, Plymouth, IA

Built 1962 Load: 15.5 t ADT: 15

150TH ST

Fair

Over: W BR FLOYD RIVER

093453101, Plymouth, IA

Built 1963 Load: 15.5 t ADT: 50

LOCAL

Fair

Over: CREEK

078361704, Audubon, IA

Built 1950 Load: 15.6 t ADT: 21

JUPITER RD

Fair

Over: WAYMAN CREEK

092043618, Clayton, IA

Built 1951 Load: 15.6 t ADT: 246

CHARIOT RD

Fair

Over: STREAM

094062705, Clayton, IA

Built 1954 Load: 15.6 t ADT: 34

140TH ST

Fair

Over: HONEY CREEK

090052701, Delaware, IA

Built 1925 Load: 15.6 t ADT: 30

FM

Fair

Over: CREEK

084E52204, Jackson, IA

Built 1978 Load: 15.6 t ADT: 45

LOCAL ROAD

Fair

Over: DRAINAGE DITCH

081221905, Polk, IA

Built 1967 Load: 15.6 t ADT: 40

LOCAL

Fair

Over: CREEK

0693206, Taylor, IA

Built 1958 Load: 15.6 t ADT: 11

410TH

Fair

Over: SHELLROCK RIVER

099203501, Worth, IA

Built 1955 Load: 15.6 t ADT: 471

LOCAL

Fair

Over: MIDDLE RIVER

077320201, Adair, IA

Built 1953 Load: 15.7 t ADT: 60

FM-150TH STREET

Fair

Over: SHOW CREEK

073353601, Adams, IA

Built 1958 Load: 15.7 t ADT: 40

LOCAL RD

Fair

Over: YELLOW RIVER

096061204, Allamakee, IA

Built 1954 Load: 15.7 t ADT: 39

FM

Fair

Over: SMALL STREAM

069182003, Appanoose, IA

Built 1948 Load: 15.7 t ADT: 70

FM

Fair

Over: FIELD STREAM

084361302, Carroll, IA

Built 1900 Load: 15.7 t ADT: 71

FM

Fair

Over: SUGAR CREEK

080020805, Cedar, IA

Built 1946 Load: 15.7 t ADT: 80

230 STREET

Fair

Over: STREAM

068401601, Fremont, IA

Built 1969 Load: 15.7 t ADT: 31

LOCAL

Fair

Over: BRANCH BEAR CREEK

087183202, Grundy, IA

Built 1954 Load: 15.7 t ADT: 39

FM

Fair

Over: DOWD CREEK

087183402, Grundy, IA

Built 1956 Load: 15.7 t ADT: 29

LOCAL

Fair

Over: BRANCH BEAVER CREEK

088180804, Grundy, IA

Built 1956 Load: 15.7 t ADT: 78

LOCAL

Fair

Over: BRANCH BEAVER CREEK

088181002, Grundy, IA

Built 1955 Load: 15.7 t ADT: 15

LOCAL ROAD

Fair

Over: MIDDLE FORK BEAVER CREEK

089172802, Grundy, IA

Built 1957 Load: 15.7 t ADT: 15

FM

Fair

Over: BEAVER CREEK ,SOUTH FORK

089173301, Grundy, IA

Built 1956 Load: 15.7 t ADT: 20

LOCAL

Fair

Over: BRANCH BEAVER CREEK

089181702, Grundy, IA

Built 1957 Load: 15.7 t ADT: 44

FM

Fair

Over: BEAVER CREEK ,BRANCH

089182001, Grundy, IA

Built 1954 Load: 15.7 t ADT: 79

LOCAL

Fair

Over: MUD CREEK

072071604, Henry, IA

Built 1953 Load: 15.7 t ADT: 62

135TH ST

Fair

Over: CRANE CREEK

098131103, Howard, IA

Built 1951 Load: 15.7 t ADT: 20

LOCAL

Fair

Over: SMALL STREAM

081122802, Iowa, IA

Built 1952 Load: 15.7 t ADT: 30

FM

Fair

Over: STUMP CREEK

071113004, Jefferson, IA

Built 1952 Load: 15.7 t ADT: 110

LOCAL

Fair

Over: TRIB S FORK ENGLISH RVR

077112003, Keokuk, IA

Built 1951 Load: 15.7 t ADT: 26

FM

Fair

Over: WHITE BREAST CREEK

072220503, Lucas, IA

Built 1954 Load: 15.7 t ADT: 50

FM

Fair

Over: SOUTH OTTER CREEK

073232109, Lucas, IA

Built 1957 Load: 15.7 t ADT: 40

FM

Fair

Over: CLANTON CREEK

075263207, Madison, IA

Built 1956 Load: 15.7 t ADT: 71

FM

Fair

Over: MUCHAKINOCK CR

074160203, Mahaska, IA

Built 1960 Load: 15.7 t ADT: 80

FM

Fair

Over: DRAINAGE DITCH #2

074160403, Mahaska, IA

Built 1951 Load: 15.7 t ADT: 40

LOCAL

Fair

Over: N COAL CREEK

074170905, Mahaska, IA

Built 1961 Load: 15.7 t ADT: 11

LOCAL

Fair

Over: DRAINAGE

074171904, Mahaska, IA

Built 1955 Load: 15.7 t ADT: 60

FM

Fair

Over: BALLINGER CREEK

076170205, Mahaska, IA

Built 1960 Load: 15.7 t ADT: 35

LOCAL

Fair

Over: DRAINAGE

077151003, Mahaska, IA

Built 1973 Load: 15.7 t ADT: 15

Showing 1,501-1,550 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.