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

FM

Poor

Over: STREAM

082202702, Marshall, IA

Built 1935 Load: 13.5 t ADT: 79

LOCAL

Poor

Over: TARKIO CREEK

071372003, Montgomery, IA

Built 1949 Load: 13.5 t ADT: 60

LOCAL

Poor

Over: SMALL STREAM

079390801, Shelby, IA

Built 1968 Load: 13.5 t ADT: 5

LOCAL

Poor

Over: WEST 102 RIVER

067352704, Taylor, IA

Built 1955 Load: 13.5 t ADT: 15

LOCAL

Poor

Over: MONTGOMERY CREEK

085262501, Boone, IA

Built 1900 Load: 13.6 t ADT: 34

210TH ST

Poor

Over: DITCH

092113401, Bremer, IA

Built 1925 Load: 13.6 t ADT: 49

320TH ST

Poor

Over: MIDDLE BR WAPSINONOC CR

079042601, Cedar, IA

Built 1930 Load: 13.6 t ADT: 20

LOCAL

Poor

Over: WHITE BREAST CREEK

071240206, Clarke, IA

Built 1971 Load: 13.6 t ADT: 60

ACORN RD

Poor

Over: SMALL

091063003, Clayton, IA

Built 1951 Load: 13.6 t ADT: 11

SCENIC RD

Poor

Over: SMALL DRY RUN

095101003, Fayette, IA

Built 1920 Load: 13.6 t ADT: 373

LOCAL

Poor

Over: DRAINAGE DITCH

089230502, Hamilton, IA

Built 1922 Load: 13.6 t ADT: 15

LOCAL

Poor

Over: SMALL STREAM

081190602, Jasper, IA

Built 1974 Load: 13.6 t ADT: 35

LOCAL

Poor

Over: STEADY RUN CREEK

074121504, Keokuk, IA

Built 1979 Load: 13.6 t ADT: 11

P14 10TH AVE

Poor

Over: E FORK DES MOINES RIVER

099303104, Kossuth, IA

Built 1900 Load: 13.6 t ADT: 34

LOCAL

Poor

Over: PLEASANT CREEK

077143305, Mahaska, IA

Built 1956 Load: 13.6 t ADT: 15

LOCAL

Poor

Over: STREAM

077162303, Mahaska, IA

Built 1953 Load: 13.6 t ADT: 60

FM

Poor

Over: LITTLE ASHER CR

084181602, Marshall, IA

Built 1916 Load: 13.6 t ADT: 118

530TH AVE

Poor

Over: BALLARD CREEK

082241502, Story, IA

Built 1953 Load: 13.6 t ADT: 50

FM

Poor

Over: CREEK

088423302, Woodbury, IA

Built 1962 Load: 13.6 t ADT: 379

LOCAL

Poor

Over: BRANCH MIDDLE RIVER

076301802, Adair, IA

Built 1948 Load: 13.7 t ADT: 15

520TH ST

Poor

Over: BR RACCOON RIVER

092352701, Buena Vista, IA

Built 1931 Load: 13.7 t ADT: 20

LOCAL

Poor

Over: E CEDAR CR.

088311501, Calhoun, IA

Built 1980 Load: 13.7 t ADT: 15

LOCAL - CHICAGO

Poor

Over: CREEK

077371501, Cass, IA

Built 1977 Load: 13.7 t ADT: 15

LOCAL

Poor

Over: DRAINAGE

089221002, Hardin, IA

Built 1976 Load: 13.7 t ADT: 26

LOCAL

Poor

Over: CLEAR CREEK

081201902, Jasper, IA

Built 1930 Load: 13.7 t ADT: 80

LOCAL ROAD

Poor

Over: ARGO SLOUGH

099431602, Lyon, IA

Built 1900 Load: 13.7 t ADT: 46

FM

Poor

Over: BADGER CREEK

077271502, Madison, IA

Built 1955 Load: 13.7 t ADT: 131

LOCAL

Poor

Over: PRICE CREEK

075170608, Mahaska, IA

Built 1970 Load: 13.7 t ADT: 71

LOCAL

Poor

Over: SNIPE CREEK

082191602, Marshall, IA

Built 1918 Load: 13.7 t ADT: 35

FM

Poor

Over: SMALL STREAM

079163403, Poweshiek, IA

Built 1948 Load: 13.7 t ADT: 15

LOCAL

Poor

Over: EAST RIVER

070322702, Taylor, IA

Built 1952 Load: 13.7 t ADT: 50

LOCAL

Poor

Over: STREAM

091263003, Wright, IA

Built 1905 Load: 13.7 t ADT: 35

LOCAL 40TH ST

Poor

Over: BLANK CR

100132501, Howard, IA

Built 1953 Load: 13.8 t ADT: 51

FM

Poor

Over: STREAM

076111202, Keokuk, IA

Built 1948 Load: 13.8 t ADT: 100

LOC 230TH AVE

Poor

Over: PRAIRIE CREEK

095273502, Kossuth, IA

Built 1976 Load: 13.8 t ADT: 15

LOCAL

Poor

Over: PLEASANT CREEK

076140403, Mahaska, IA

Built 1956 Load: 13.8 t ADT: 5

LOCAL

Poor

Over: RAVEN CREEK

082160604, Tama, IA

Built 1940 Load: 13.8 t ADT: 29

FM

Poor

Over: BR IOWAY CREEK

085250403, Boone, IA

Built 1916 Load: 13.9 t ADT: 20

CEDAR\JONES RD

Poor

Over: SMALL

082030101, Cedar, IA

Built 1980 Load: 13.9 t ADT: 11

FM 197 AVE

Poor

Over: SMALL STREAM

088051506, Delaware, IA

Built 1967 Load: 13.9 t ADT: 962

FM & NASH TRAIL

Poor

Over: ALLEN CREEK

081432604, Harrison, IA

Built 1976 Load: 13.9 t ADT: 20

LOCAL

Poor

Over: TETE DES MORTS CREEK

087E32302, Jackson, IA

Built 1981 Load: 13.9 t ADT: 15

200TH AVE.

Poor

Over: SMALL CREEK

083042402, Jones, IA

Built 1967 Load: 13.9 t ADT: 51

LOCAL

Poor

Over: CROOKED CREEK

076101401, Keokuk, IA

Built 1952 Load: 13.9 t ADT: 30

180TH ST

Poor

Over: DD 88

089321601, Calhoun, IA

Built 1900 Load: 14.0 t ADT: 26

FM - 710TH

Poor

Over: WATERWAY

076350106, Cass, IA

Built 1955 Load: 14.0 t ADT: 50

LOCAL

Poor

Over: SMALL STREAM

081202707, Jasper, IA

Built 1970 Load: 14.0 t ADT: 51

FM

Poor

Over: DRAINAGE

075282203, Madison, IA

Built 1930 Load: 14.0 t ADT: 180

LOCAL

Poor

Over: DRAINAGE

076161903, Mahaska, IA

Built 1956 Load: 14.0 t ADT: 15

PRIVATE (SDB)

Poor

Over: STREAM (SDB)

079222604, Polk, IA

Built 1950 Load: 14.0 t ADT: 10

Showing 17,101-17,150 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.