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: STREAM

089443401, Woodbury, IA

Built 1915 Load: 23.8 t ADT: 80

LOCAL

Poor

Over: CREEK

081342403, Audubon, IA

Built 1950 Load: 23.9 t ADT: 5

320TH ST

Poor

Over: E BR WAPSINONOC CR

079032901, Cedar, IA

Built 1975 Load: 23.9 t ADT: 90

GRANT AVE

Poor

Over: PIONEER CREEK

082030604, Cedar, IA

Built 1976 Load: 23.9 t ADT: 34

160TH ST

Poor

Over: N BR VOLGA RIVER

093092101, Fayette, IA

Built 1950 Load: 23.9 t ADT: 34

LOCAL

Poor

Over: BRUSH CREEK

081170202, Jasper, IA

Built 1988 Load: 23.9 t ADT: 5

LOCAL

Poor

Over: STREAM

071110608, Jefferson, IA

Built 1900 Load: 23.9 t ADT: 30

FM

Poor

Over: STREAM

076131303, Keokuk, IA

Built 1972 Load: 23.9 t ADT: 30

S23 200TH AVE

Poor

Over: BNSF RR

072221402, Lucas, IA

Built 1937 Load: 23.9 t ADT: 1,090

RITCHIE RD

Poor

Over: MUD CREEK

091443103, Plymouth, IA

Built 1948 Load: 23.9 t ADT: 15

TAMARACK ROAD

Poor

Over: OVER BNSF RR

077411905, Pottawattamie, IA

Built 1930 Load: 23.9 t ADT: 1,325

ROSEWOOD ROAD

Poor

Over: SECOND CREEK

076380601, Pottawattamie, IA

Built 1949 Load: 23.9 t ADT: 15

FM

Poor

Over: BRANCH SALT CREEK

083131801, Tama, IA

Built 1968 Load: 23.9 t ADT: 59

FM

Poor

Over: STREAM

087E22104, Dubuque, IA

Built 1941 Load: 24.0 t ADT: 25

FM

Poor

Over: CREEK

090E12205, Dubuque, IA

Built 1920 Load: 24.0 t ADT: 310

V AVE

Poor

Over: STOE CREEK

092101504, Fayette, IA

Built 1949 Load: 24.0 t ADT: 44

ROOSEVELT AVE

Poor

Over: DD

091432802, Plymouth, IA

Built 1900 Load: 24.0 t ADT: 15

DIAMOND AVE

Poor

Over: BEAVER CREEK

093482702, Plymouth, IA

Built 1900 Load: 24.0 t ADT: 26

LOCAL

Poor

Over: EAST BRANCH SALT CREEK

084130302, Tama, IA

Built 1937 Load: 24.0 t ADT: 33

LOCAL

Poor

Over: SMALL STREAM

073290801, Union, IA

Built 1980 Load: 24.0 t ADT: 11

LOCAL

Poor

Over: CREEK

070110510, Van Buren, IA

Built 1974 Load: 24.0 t ADT: 15

PIERCE ST

Poor

Over: PAINTER CREEK

075253005, Warren, IA

Built 1945 Load: 24.0 t ADT: 11

LOCAL 560TH ST.

Poor

Over: ROCK CREEK

091411601, Cherokee, IA

Built 1946 Load: 24.1 t ADT: 20

LOCAL ROAD

Poor

Over: MIDDLE FORK BEAVER CREEK

089172902, Grundy, IA

Built 1948 Load: 24.1 t ADT: 39

LOCAL

Poor

Over: DRAINAGE

077271602, Madison, IA

Built 1940 Load: 24.1 t ADT: 90

J-28 / 170TH ST

Poor

Over: WEST TARKIO RIVER

069380901, Page, IA

Built 1952 Load: 24.1 t ADT: 120

280TH ST

Poor

Over: PERRY CREEK

090470401, Plymouth, IA

Built 1900 Load: 24.1 t ADT: 20

IA 92

Poor

Over: INDIAN CREEK

0.7 Mi. W of Jct. SR M-47, Pottawattamie, IA

Built 1938 Load: 24.1 t ADT: 1,180

LOCAL

Poor

Over: N BUFFALO CREEK

100253602, Winnebago, IA

Built 1949 Load: 24.1 t ADT: 11

FM

Poor

Over: OPOSSUM CREEK

084101501, Benton, IA

Built 1959 Load: 24.2 t ADT: 1,090

170TH ST

Poor

Over: VOLGA RIVER

093091703, Fayette, IA

Built 1941 Load: 24.2 t ADT: 39

LOCAL

Poor

Over: DRAINAGE DITCH

087242101, Hamilton, IA

Built 1923 Load: 24.2 t ADT: 30

LOCAL

Poor

Over: BRANCH OF SALT CREEK

085152604, Tama, IA

Built 1983 Load: 24.2 t ADT: 33

LOCAL

Poor

Over: SALT CREEK

085153304, Tama, IA

Built 1940 Load: 24.2 t ADT: 20

LOCAL/VICTORIA

Poor

Over: SMALL

074362101, Cass, IA

Built 1959 Load: 24.3 t ADT: 41

FM - YANKTON

Poor

Over: WATERWAY

074363301, Cass, IA

Built 1958 Load: 24.3 t ADT: 50

LOCAL/RICHLAND

Poor

Over: WATERWAY

075363301, Cass, IA

Built 1959 Load: 24.3 t ADT: 40

LOCAL/RICHLAND

Poor

Over: WATERWAY

075363301, Cass, IA

Built 1959 Load: 24.3 t ADT: 40

LOCAL

Poor

Over: SPRING BRANCH CREEK

094132703, Chickasaw, IA

Built 1961 Load: 24.3 t ADT: 91

FM

Poor

Over: BOONE RIVER

089253101, Hamilton, IA

Built 1964 Load: 24.3 t ADT: 499

2680 270TH ST

Poor

Over: EAST BRANCH IA RIVER

096230701, Hancock, IA

Built 1958 Load: 24.3 t ADT: 11

LOCAL

Poor

Over: IOWA RIVER (SOUTH FORK)

087210201, Hardin, IA

Built 1956 Load: 24.3 t ADT: 29

FA-GASTON AVE

Poor

Over: DRAINAGE

072410605, Mills, IA

Built 1951 Load: 24.3 t ADT: 139

FM

Poor

Over: AVERY CREEK

071160203, Monroe, IA

Built 1958 Load: 24.3 t ADT: 80

FM

Poor

Over: LITTLE TARKIO

071383501, Montgomery, IA

Built 1958 Load: 24.3 t ADT: 219

FM

Poor

Over: CRABAPPLE CREEK

073393501, Montgomery, IA

Built 1958 Load: 24.3 t ADT: 199

300TH ST

Poor

Over: MUD CREEK

090451301, Plymouth, IA

Built 1950 Load: 24.3 t ADT: 50

190TH ST

Poor

Over: BULL RUN

092472101, Plymouth, IA

Built 1961 Load: 24.3 t ADT: 50

CO.RD.

Poor

Over: STREAM

083132002, Tama, IA

Built 1965 Load: 24.3 t ADT: 20

LOCAL

Poor

Over: CREEK

073141703, Wapello, IA

Built 1925 Load: 24.3 t ADT: 21

Showing 18,451-18,500 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.