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

US 18 & 52

Fair

Over: BRANCH ROBERTS CREEK

0.3 MI. W OF JCT. SR W64, Clayton, IA

Built 1967 Load: 22.2 t ADT: 4,140

IA 39

Fair

Over: OTTER CREEK

5.6 mi. N of jct. US 59, Crawford, IA

Built 1951 Load: 22.2 t ADT: 2,580

LOCAL

Fair

Over: SMALL STREAM

085370201, Crawford, IA

Built 1965 Load: 22.2 t ADT: 50

LOCAL

Fair

Over: CREEK

087E41403, Jackson, IA

Built 1930 Load: 22.2 t ADT: 71

LOCAL

Fair

Over: CEDAR CREEK

075121003, Keokuk, IA

Built 1983 Load: 22.2 t ADT: 60

LCL-302ND ST

Fair

Over: STREAM

073413004, Mills, IA

Built 1981 Load: 22.2 t ADT: 34

LOCAL

Fair

Over: LITTLE ROCK RIVER

100421901, Osceola, IA

Built 1989 Load: 22.2 t ADT: 21

LOCAL

Fair

Over: OLD CHANNEL DES MOINES R

094312801, Palo Alto, IA

Built 1931 Load: 22.2 t ADT: 72

LOCAL ROAD

Fair

Over: MUD CREEK

079221703, Polk, IA

Built 1900 Load: 22.2 t ADT: 210

680TH AVE

Fair

Over: DYE CREEK

083211802, Story, IA

Built 1967 Load: 22.2 t ADT: 319

IRR-LOCAL

Fair

Over: BENNETT CREEK

083153106, Tama, IA

Built 1986 Load: 22.2 t ADT: 128

LOCAL

Fair

Over: HONEY CREEK

068333201, Taylor, IA

Built 1964 Load: 22.2 t ADT: 20

FM

Fair

Over: WALNUT CREEK (TEN MILE)

098090105, Winneshiek, IA

Built 1950 Load: 22.2 t ADT: 344

LOCAL

Fair

Over: STREAM

089433504, Woodbury, IA

Built 2005 Load: 22.2 t ADT: 26

LOCAL

Fair

Over: MIDDLE RIVER

076301801, Adair, IA

Built 1915 Load: 22.3 t ADT: 30

265TH STREET

Fair

Over: W BRANCH 102 RIVER

071332903, Adams, IA

Built 1965 Load: 22.3 t ADT: 50

WALNUT AVENUE

Fair

Over: EAST NODAWAY RIVER

073321404, Adams, IA

Built 1980 Load: 22.3 t ADT: 71

FM

Fair

Over: LITTLE BEAR CREEK

083090403, Benton, IA

Built 1974 Load: 22.3 t ADT: 79

LOCAL

Fair

Over: PRATT CK

085110502, Benton, IA

Built 1976 Load: 22.3 t ADT: 60

LOCAL

Fair

Over: PRATT CK

086112702, Benton, IA

Built 1977 Load: 22.3 t ADT: 30

RICKARD RD

Fair

Over: SPRING CREEK

88-11-35-01-10, Black Hawk, IA

Built 1970 Load: 22.3 t ADT: 78

NEWELL ST

Fair

Over: ELK RUN CREEK

89-12-22-03-10, Black Hawk, IA

Built 1970 Load: 22.3 t ADT: 97

150TH ST

Fair

Over: STREAM

093153401, Butler, IA

Built 1971 Load: 22.3 t ADT: 15

FLOYD LINE ST

Fair

Over: FLOOD CREEK

093160301, Butler, IA

Built 1966 Load: 22.3 t ADT: 15

FM

Fair

Over: COLDWATER CREEK

093181002, Butler, IA

Built 1978 Load: 22.3 t ADT: 59

LOCAL

Fair

Over: BOYLAN CREEK

093183204, Butler, IA

Built 1979 Load: 22.3 t ADT: 15

LOCAL

Fair

Over: LAKE CREEK

087320503, Calhoun, IA

Built 1967 Load: 22.3 t ADT: 26

LOCAL

Fair

Over: LAKE CR.

087332501, Calhoun, IA

Built 1965 Load: 22.3 t ADT: 15

LOCAL - 740TH

Fair

Over: CROOKED CREEK

077340402, Cass, IA

Built 1984 Load: 22.3 t ADT: 145

200TH

Fair

Over: SUGAR CREEK

081022901, Cedar, IA

Built 1985 Load: 22.3 t ADT: 60

IA 31

Fair

Over: STRATTON CREEK

0.1 mi. N of SR C66, Cherokee, IA

Built 1922 Load: 22.3 t ADT: 1,330

LOCAL-490TH ST.

Fair

Over: MAPLE RIVER

092390901, Cherokee, IA

Built 1975 Load: 22.3 t ADT: 15

FM

Fair

Over: FABIUS CREEK

068153404, Davis, IA

Built 1984 Load: 22.3 t ADT: 25

LOCAL

Fair

Over: SOUTH SOAP CREEK

070153004, Davis, IA

Built 1979 Load: 22.3 t ADT: 11

US 69

Fair

Over: LITTLE RIVER

3.8 MI. N OF SR J66, Decatur, IA

Built 1953 Load: 22.3 t ADT: 820

LOCAL

Fair

Over: CEDAR FORK CREEK

071041304, Des Moines, IA

Built 1974 Load: 22.3 t ADT: 35

LOCAL

Fair

Over: EAST FORK CROOKED CREEK

072040503, Des Moines, IA

Built 1970 Load: 22.3 t ADT: 26

FM

Fair

Over: FLOOD CREEK

095171004, Floyd, IA

Built 1970 Load: 22.3 t ADT: 59

LOCAL

Fair

Over: BEAVER CREEK

095182604, Floyd, IA

Built 1967 Load: 22.3 t ADT: 33

LOCAL

Fair

Over: BEAVER CREEK

095182701, Floyd, IA

Built 1971 Load: 22.3 t ADT: 20

LOCAL RD

Fair

Over: FLOOD CREEK

096181001, Floyd, IA

Built 1976 Load: 22.3 t ADT: 26

FM RAVEN AVE

Fair

Over: BAILEYE CREEK

093201302, Franklin, IA

Built 1967 Load: 22.3 t ADT: 59

LOCAL

Fair

Over: BEAVER CREEK

078310308, Guthrie, IA

Built 1970 Load: 22.3 t ADT: 20

LOCAL

Fair

Over: SOUTH FORK MIDDLE RIVER

078323304, Guthrie, IA

Built 1984 Load: 22.3 t ADT: 40

LOCAL

Fair

Over: MASON CREEK

079321303, Guthrie, IA

Built 1985 Load: 22.3 t ADT: 34

LOCAL

Fair

Over: CROOKED CREEK

073052201, Henry, IA

Built 1959 Load: 22.3 t ADT: 123

LOCAL

Fair

Over: SILVER CREEK

088391601, Ida, IA

Built 1985 Load: 22.3 t ADT: 15

LOCAL

Fair

Over: ASHTON CREEK

089410902, Ida, IA

Built 1983 Load: 22.3 t ADT: 26

FM

Fair

Over: BRUSH CREEK

072083606, Jefferson, IA

Built 1975 Load: 22.3 t ADT: 50

LOCAL

Fair

Over: WALNUT CREEK

073092404, Jefferson, IA

Built 1979 Load: 22.3 t ADT: 15

Showing 3,251-3,300 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.