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 T-35

Fair

Over: DRAINAGE

071172504, Monroe, IA

Built 1964 Load: 14.4 t ADT: 60

JADE AVE

Fair

Over: DRAINAGE

090460304, Plymouth, IA

Built 1989 Load: 14.4 t ADT: 50

JESTER PARK

Fair

Over: PAW CREEK

081253303, Polk, IA

Built 1963 Load: 14.4 t ADT: 29

FM

Fair

Over: LONG CREEK

070263205, Decatur, IA

Built 1957 Load: 14.5 t ADT: 627

VINCENT AVE SE

Fair

Over: STREAM

078051004, Johnson, IA

Built 1970 Load: 14.5 t ADT: 20

NW CHAMBERS AVE

Fair

Over: STREAM

081080904, Johnson, IA

Built 1972 Load: 14.5 t ADT: 92

340TH

Fair

Over: SPRING CREEK

097160501, Mitchell, IA

Built 1927 Load: 14.5 t ADT: 97

395TH

Fair

Over: BURR OAK CREEK

098160503, Mitchell, IA

Built 1920 Load: 14.5 t ADT: 15

LOCAL

Fair

Over: LITTLE OCHEYDAN RIVER

098392802, Osceola, IA

Built 1941 Load: 14.5 t ADT: 21

LOCAL

Fair

Over: LITTLE OCHEYDAN RIVER

098401401, Osceola, IA

Built 1940 Load: 14.5 t ADT: 21

LOCAL

Fair

Over: DRY RUN

099392002, Osceola, IA

Built 1936 Load: 14.5 t ADT: 15

LOCAL

Fair

Over: STREAM

099401902, Osceola, IA

Built 1941 Load: 14.5 t ADT: 15

730TH AVE

Fair

Over: MARSHALL-STORY DD#2

082210102, Story, IA

Built 1944 Load: 14.5 t ADT: 30

140TH ST

Fair

Over: HAMILTON-STORY 1 OPEN DD

085242601, Story, IA

Built 1935 Load: 14.5 t ADT: 20

FM

Fair

Over: WEST 102 RIVER

067351501, Taylor, IA

Built 1939 Load: 14.5 t ADT: 210

FM

Fair

Over: EAST 102 RIVER

068343504, Taylor, IA

Built 1940 Load: 14.5 t ADT: 349

FM

Fair

Over: WEST BRANCH 102 RIVER

070343108, Taylor, IA

Built 1947 Load: 14.5 t ADT: 26

JIGSAW RD

Fair

Over: CEDAR CREEK

093033103, Clayton, IA

Built 1925 Load: 14.6 t ADT: 21

NORWOOD AVE

Fair

Over: HONEY CREEK

078433306, Harrison, IA

Built 1900 Load: 14.6 t ADT: 5

FM

Fair

Over: MOON CREEK

077141801, Mahaska, IA

Built 1965 Load: 14.6 t ADT: 190

LOCAL

Fair

Over: CYLINDER CREEK

097312702, Palo Alto, IA

Built 1972 Load: 14.6 t ADT: 15

HICKORY ROAD

Fair

Over: LITTLE SILVER CREEK

075411801, Pottawattamie, IA

Built 1985 Load: 14.6 t ADT: 11

LOCAL

Fair

Over: CREEK

096092806, Winneshiek, IA

Built 1900 Load: 14.6 t ADT: 26

LOCAL

Fair

Over: PAINT CREEK

097041703, Allamakee, IA

Built 1976 Load: 14.7 t ADT: 5

FM- 650TH ST

Fair

Over: MAPLE RIVER

090393303, Cherokee, IA

Built 1961 Load: 14.7 t ADT: 290

142 STREET

Fair

Over: PLUM CREEK

070422903, Fremont, IA

Built 1960 Load: 14.7 t ADT: 89

HICKORY ROAD

Fair

Over: MIDDLE SILVER CREEK

075411701, Pottawattamie, IA

Built 1985 Load: 14.7 t ADT: 15

LOCAL

Fair

Over: SAND CREEK

070281207, Ringgold, IA

Built 1972 Load: 14.7 t ADT: 15

LOCAL

Fair

Over: MILL CREEK TRIBUTARY

081400909, Shelby, IA

Built 1967 Load: 14.7 t ADT: 30

LOCAL

Fair

Over: STREAM

076313101, Adair, IA

Built 1955 Load: 14.8 t ADT: 21

FM - DALLAS

Fair

Over: TROUBLESOME RIVER

077352101, Cass, IA

Built 1959 Load: 14.8 t ADT: 20

LOCAL

Fair

Over: DEEP RIVER

078120602, Iowa, IA

Built 1962 Load: 14.8 t ADT: 11

500TH ST SE

Fair

Over: STREAM

078051301, Johnson, IA

Built 1971 Load: 14.8 t ADT: 35

LOCAL

Fair

Over: E FK GRAND RIVER

070292501, Ringgold, IA

Built 1936 Load: 14.8 t ADT: 5

LOCAL

Fair

Over: STREAM

086363402, Sac, IA

Built 1934 Load: 14.8 t ADT: 40

240TH AVE

Fair

Over: WAPSIPINICON RIVER

080E41208, Scott, IA

Built 1961 Load: 14.8 t ADT: 1,140

LOCAL FARM LANE

Fair

Over: BR WILLIAMS CREEK

096051703, Allamakee, IA

Built 1975 Load: 14.9 t ADT: 5

LOCAL

Fair

Over: HOCKETT CREEK

083373002, Crawford, IA

Built 1900 Load: 14.9 t ADT: 21

FM

Fair

Over: MILLER CREEK

084372906, Crawford, IA

Built 1958 Load: 14.9 t ADT: 368

FM

Fair

Over: EAST BOYER RIVER

084383604, Crawford, IA

Built 1954 Load: 14.9 t ADT: 110

FM

Fair

Over: JIM CREEK

077291502, Madison, IA

Built 1962 Load: 14.9 t ADT: 597

LOCAL

Fair

Over: DRAINAGE

077142704, Mahaska, IA

Built 1954 Load: 14.9 t ADT: 15

FM

Fair

Over: SMALL STREAM

074210504, Marion, IA

Built 1950 Load: 14.9 t ADT: 45

LOCAL RD

Fair

Over: SMALL

098390603, Osceola, IA

Built 1953 Load: 14.9 t ADT: 5

LOCAL

Fair

Over: STREAM

099390801, Osceola, IA

Built 1939 Load: 14.9 t ADT: 90

LOCAL

Fair

Over: LITTLE OCHEYEDAN RIVER

099403001, Osceola, IA

Built 1950 Load: 14.9 t ADT: 21

LOCAL RD

Fair

Over: SNOW CREEK

100421601, Osceola, IA

Built 1939 Load: 14.9 t ADT: 21

LOCAL

Fair

Over: D D #106

092371101, Buena Vista, IA

Built 1978 Load: 15.0 t ADT: 34

LOCAL

Fair

Over: SOLDIER CREEK

093372301, Buena Vista, IA

Built 1977 Load: 15.0 t ADT: 34

FM

Fair

Over: BRUSH CREEK

069273606, Decatur, IA

Built 1954 Load: 15.0 t ADT: 60

Showing 1,401-1,450 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.