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: WOLF CREEK

086180201, Grundy, IA

Built 1978 Load: 25.7 t ADT: 49

FM

Poor

Over: S COPPER CREEK

084E52804, Jackson, IA

Built 1974 Load: 25.7 t ADT: 1,070

FM

Poor

Over: SMALL STREAM

076051101, Louisa, IA

Built 1969 Load: 25.7 t ADT: 840

FM

Poor

Over: N TIMBER CREEK

083192002, Marshall, IA

Built 1963 Load: 25.7 t ADT: 903

LOCAL

Poor

Over: SMALL STREAM

080160602, Poweshiek, IA

Built 1978 Load: 25.7 t ADT: 71

WELLS FERRY RD

Poor

Over: CREEK

078E50606, Scott, IA

Built 1964 Load: 25.7 t ADT: 1,010

LOCAL

Poor

Over: BR STEIN CK

084123001, Benton, IA

Built 1971 Load: 25.8 t ADT: 5

LOCAL

Poor

Over: TURKEY CREEK

077342906, Cass, IA

Built 1981 Load: 25.8 t ADT: 21

222ND ST

Poor

Over: WEST BEAVER CREEK

083290303, Greene, IA

Built 1921 Load: 25.8 t ADT: 300

LOCAL RD

Poor

Over: SOUTH FORK BEAVER CREEK

088180903, Grundy, IA

Built 1977 Load: 25.8 t ADT: 39

LOCAL

Poor

Over: BRANCH S TIMBER CREEK

082180801, Marshall, IA

Built 1951 Load: 25.8 t ADT: 15

LOCAL

Poor

Over: DRAINAGE DITCH

098250601, Winnebago, IA

Built 1950 Load: 25.8 t ADT: 35

LOCAL ROAD

Poor

Over: CREEK

099091007, Winneshiek, IA

Built 1900 Load: 25.8 t ADT: 108

LOCAL

Poor

Over: SPRING CREEK

094112301, Chickasaw, IA

Built 1991 Load: 25.9 t ADT: 47

MESQUITE RD

Poor

Over: PECK CREEK

091030103, Clayton, IA

Built 1913 Load: 25.9 t ADT: 113

BIXBY RD

Poor

Over: NAGLE CREEK

092060906, Clayton, IA

Built 1960 Load: 25.9 t ADT: 62

EDGE RD.

Poor

Over: BELL CR

094070804, Fayette, IA

Built 1954 Load: 25.9 t ADT: 20

180TH ST

Poor

Over: TURKEY RIVER

097110501, Howard, IA

Built 1986 Load: 25.9 t ADT: 30

150TH AVE.

Poor

Over: SMALL CREEK

086031402, Jones, IA

Built 1959 Load: 25.9 t ADT: 238

FM

Poor

Over: LONG CREEK

075053202, Louisa, IA

Built 1963 Load: 25.9 t ADT: 250

L14

Poor

Over: TOM CREEK

100442304, Lyon, IA

Built 1964 Load: 25.9 t ADT: 509

FM

Poor

Over: LUTES CREEK

082172904, Marshall, IA

Built 1940 Load: 25.9 t ADT: 29

FA-BARRUS RD

Poor

Over: KEG CREEK

073420839, Mills, IA

Built 1951 Load: 25.9 t ADT: 698

FM

Poor

Over: BRANCH OTTER CREEK

083141701, Tama, IA

Built 1940 Load: 25.9 t ADT: 25

FM

Poor

Over: EAST RIVER

070323301, Taylor, IA

Built 1950 Load: 25.9 t ADT: 40

FM 570TH ST

Poor

Over: GERE CREEK

093413601, Cherokee, IA

Built 1951 Load: 26.0 t ADT: 50

FM-150TH ST

Poor

Over: CRANE CREEK

098132305, Howard, IA

Built 1968 Load: 26.0 t ADT: 590

NORTHBROOK DR

Poor

Over: DRY CREEK

000000000, Linn, IA

Built 1972 Load: 26.0 t ADT: 1,755

LOCAL

Poor

Over: HAWK RUN

075200702, Marion, IA

Built 1925 Load: 26.0 t ADT: 11

FM

Poor

Over: BRANCH LITTLE SIOUX RVR

093382601, Buena Vista, IA

Built 1967 Load: 26.1 t ADT: 120

FM - 335TH ST

Poor

Over: SMALL CREEK

078413503, Harrison, IA

Built 1952 Load: 26.1 t ADT: 71

M AVE

Poor

Over: IOWA RIVER

081101902, Iowa, IA

Built 1950 Load: 26.1 t ADT: 2,340

QUARTZ ST

Poor

Over: SMALL STREAM

078203402, Jasper, IA

Built 1940 Load: 26.1 t ADT: 35

LOCAL ROAD

Poor

Over: EMERY CREEK

099443001, Lyon, IA

Built 1900 Load: 26.1 t ADT: 35

FM

Poor

Over: YANKEE RUN CREEK

081010210, Cedar, IA

Built 1957 Load: 26.2 t ADT: 740

INDIAN AVE

Poor

Over: PIONEER CREEK

082030402, Cedar, IA

Built 1976 Load: 26.2 t ADT: 20

BUCK CREEK RD

Poor

Over: STREAM

093033605, Clayton, IA

Built 1954 Load: 26.2 t ADT: 79

LOCAL

Poor

Over: CREEK

089022404, Dubuque, IA

Built 1971 Load: 26.2 t ADT: 20

FM

Poor

Over: SUGAR CREEK

068072403, Lee, IA

Built 1968 Load: 26.2 t ADT: 340

LINCOLN RD

Poor

Over: TRIB TO BLACK HAWK CREEK

87-14-03-02-10, Black Hawk, IA

Built 1900 Load: 26.3 t ADT: 177

FM

Poor

Over: S WYACONDAH DITCH

068141204, Davis, IA

Built 1968 Load: 26.3 t ADT: 480

FM

Poor

Over: FOX RIVER

069132703, Davis, IA

Built 1962 Load: 26.3 t ADT: 890

FM 130 AVE

Poor

Over: SANDHAGEN CREEK

090062808, Delaware, IA

Built 1965 Load: 26.3 t ADT: 825

FM

Poor

Over: WOLF CREEK

086182301, Grundy, IA

Built 1966 Load: 26.3 t ADT: 187

FM

Poor

Over: CHERRY CREEK

080192009, Jasper, IA

Built 1970 Load: 26.3 t ADT: 770

FM

Poor

Over: STREAM

076101101, Keokuk, IA

Built 1966 Load: 26.3 t ADT: 80

FM

Poor

Over: MUD CREEK

098460406, Lyon, IA

Built 1961 Load: 26.3 t ADT: 509

FM

Poor

Over: LITTLE MOSQUITO CREEK

078023103, Muscatine, IA

Built 1964 Load: 26.3 t ADT: 990

LOCAL

Poor

Over: STREAM

078142401, Poweshiek, IA

Built 1949 Load: 26.3 t ADT: 26

FM

Poor

Over: BACON CREEK

088420402, Woodbury, IA

Built 1967 Load: 26.3 t ADT: 359

Showing 18,651-18,700 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.