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

Fair

Over: WILLOW CREEK

083411702, Crawford, IA

Built 1950 Load: 24.5 t ADT: 5

FM

Fair

Over: MIDDLE WILLOW CREEK

083412904, Crawford, IA

Built 1950 Load: 24.5 t ADT: 11

LOCAL

Fair

Over: SMALL STREAM

084403502, Crawford, IA

Built 1996 Load: 24.5 t ADT: 51

LOCAL

Fair

Over: BEAVER CREEK

085400102, Crawford, IA

Built 1971 Load: 24.5 t ADT: 21

LOCAL

Fair

Over: BR PANTHER CREEK

080292402, Dallas, IA

Built 1981 Load: 24.5 t ADT: 62

FM

Fair

Over: N WYACONDAH CREEK

068130804, Davis, IA

Built 1965 Load: 24.5 t ADT: 420

FM

Fair

Over: STEEL CREEK

068241403, Decatur, IA

Built 1984 Load: 24.5 t ADT: 10

FM

Fair

Over: HAIGHT CREEK

071021203, Des Moines, IA

Built 1909 Load: 24.5 t ADT: 60

GROUSE AVENUE

Fair

Over: DRAINAGE DITCH NO 6

090210602, Franklin, IA

Built 1967 Load: 24.5 t ADT: 11

FINCH AVE

Fair

Over: SMALL STREAM

092220102, Franklin, IA

Built 1966 Load: 24.5 t ADT: 30

HEATHER STREET

Fair

Over: DD 30 SPRING CREEK

092212002, Franklin, IA

Built 1964 Load: 24.5 t ADT: 160

FM

Fair

Over: BRANCH BEAVER CREEK

089173402, Grundy, IA

Built 1971 Load: 24.5 t ADT: 39

LOCAL

Fair

Over: MIDDLE RIVER

078323503, Guthrie, IA

Built 1993 Load: 24.5 t ADT: 5

LOCAL

Fair

Over: TRIB TO MIDDLE RIVER

078332402, Guthrie, IA

Built 1990 Load: 24.5 t ADT: 34

FM

Fair

Over: TRIB TO MASON CREEK

079322603, Guthrie, IA

Built 1983 Load: 24.5 t ADT: 50

LOCAL

Fair

Over: TRIB. TO TROUBLESOME

079330802, Guthrie, IA

Built 1986 Load: 24.5 t ADT: 40

LOCAL

Fair

Over: STREAM

080322002, Guthrie, IA

Built 1988 Load: 24.5 t ADT: 26

FM

Fair

Over: CREEK

086190513, Hardin, IA

Built 1967 Load: 24.5 t ADT: 285

FM

Fair

Over: SUGAR CREEK

073071504, Henry, IA

Built 1974 Load: 24.5 t ADT: 60

160TH ST

Fair

Over: WAPSIPINICON RIVER

098143001, Howard, IA

Built 1970 Load: 24.5 t ADT: 35

LOCAL 70TH ST

Fair

Over: CRANE CREEK

099141201, Howard, IA

Built 1979 Load: 24.5 t ADT: 47

FM

Fair

Over: CREEK

086393201, Ida, IA

Built 1970 Load: 24.5 t ADT: 159

LOCAL

Fair

Over: CREEK

086411001, Ida, IA

Built 1960 Load: 24.5 t ADT: 50

LOCAL

Fair

Over: SMALL STREAM

087402103, Ida, IA

Built 1966 Load: 24.5 t ADT: 110

FM

Fair

Over: BATTLE CREEK

087410102, Ida, IA

Built 1968 Load: 24.5 t ADT: 499

L51 BRADY AVE

Fair

Over: CREEK

087412102, Ida, IA

Built 1959 Load: 24.5 t ADT: 429

FM

Fair

Over: UNNAMED CREEK

088412402, Ida, IA

Built 1968 Load: 24.5 t ADT: 499

L67 EAGLE AVE

Fair

Over: EAST FORK BATTLE CREEK

088413604, Ida, IA

Built 1968 Load: 24.5 t ADT: 499

FM

Fair

Over: ASHTON CREEK

089410304, Ida, IA

Built 1969 Load: 24.5 t ADT: 40

LOCAL

Fair

Over: TEENER CREEK

078093206, Iowa, IA

Built 1975 Load: 24.5 t ADT: 30

LOCAL

Fair

Over: STREAM

079091004, Iowa, IA

Built 1977 Load: 24.5 t ADT: 30

LOCAL

Fair

Over: CONVEY CREEK

079091503, Iowa, IA

Built 1977 Load: 24.5 t ADT: 15

LOCAL

Fair

Over: SMALL STREAM

079093103, Iowa, IA

Built 1974 Load: 24.5 t ADT: 20

FM

Fair

Over: STREAM

079110502, Iowa, IA

Built 1981 Load: 24.5 t ADT: 570

FM

Fair

Over: STREAM

079113002, Iowa, IA

Built 1972 Load: 24.5 t ADT: 80

FM

Fair

Over: SMALL

080092101, Iowa, IA

Built 1963 Load: 24.5 t ADT: 80

M AVE

Fair

Over: STREAM

080100602, Iowa, IA

Built 1953 Load: 24.5 t ADT: 1,790

FM

Fair

Over: SMALL

081092412, Iowa, IA

Built 1959 Load: 24.5 t ADT: 210

FM

Fair

Over: SMALL

081102103, Iowa, IA

Built 1966 Load: 24.5 t ADT: 1,150

FM

Fair

Over: SMALL

081102303, Iowa, IA

Built 1966 Load: 24.5 t ADT: 1,150

FM

Fair

Over: SMALL STREAM

081110206, Iowa, IA

Built 1983 Load: 24.5 t ADT: 1,230

FM

Fair

Over: HONEY CREEK

081122806, Iowa, IA

Built 1981 Load: 24.5 t ADT: 40

LOCAL

Fair

Over: STREAM

073090401, Jefferson, IA

Built 1966 Load: 24.5 t ADT: 15

TAFT AVE

Fair

Over: STREAM

079053202, Johnson, IA

Built 1966 Load: 24.5 t ADT: 734

MUSCATINE AVE

Fair

Over: RALSTON CK S BRANCH

079061400, Johnson, IA

Built 1972 Load: 24.5 t ADT: 9,524

LOC 440TH ST

Fair

Over: DRAINAGE DITCH #82

099271601, Kossuth, IA

Built 1986 Load: 24.5 t ADT: 41

J 40

Fair

Over: SMALL NATURAL STREAM

068041904, Lee, IA

Built 1931 Load: 24.5 t ADT: 2,300

FM

Fair

Over: LAMALEES CREEK

066052601, Lee, IA

Built 1950 Load: 24.5 t ADT: 60

FM

Fair

Over: SMALL STREAM

066061401, Lee, IA

Built 1950 Load: 24.5 t ADT: 650

FM

Fair

Over: SMALL STREAM

066061404, Lee, IA

Built 1949 Load: 24.5 t ADT: 90

Showing 3,951-4,000 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.