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: CREEK

080361902, Audubon, IA

Built 1926 Load: 16.5 t ADT: 11

FM

Poor

Over: SMALL STREAM

085100602, Benton, IA

Built 1925 Load: 16.5 t ADT: 940

FM

Poor

Over: BRUSH CREEK

069252401, Decatur, IA

Built 1980 Load: 16.5 t ADT: 60

LOCAL

Poor

Over: ALLOWAY CREEK

081181601, Jasper, IA

Built 1974 Load: 16.5 t ADT: 11

MATSELL PK RD

Poor

Over: WAPSIPINICON RIVER

085053606, Linn, IA

Built 1939 Load: 16.5 t ADT: 147

WALNUT AVE

Poor

Over: WAPSIPINICON RIVER

099151402, Mitchell, IA

Built 1940 Load: 16.5 t ADT: 462

LOCAL

Poor

Over: OTTER CREEK

099421102, Osceola, IA

Built 1949 Load: 16.5 t ADT: 5

LOCAL ROAD

Poor

Over: SMALL STREAM

086382201, Sac, IA

Built 1932 Load: 16.5 t ADT: 30

FIELD ENTRANCE

Poor

Over: SIDE DITCH

067320102, Taylor, IA

Built 1980 Load: 16.5 t ADT: 10

EMMETT AVE

Poor

Over: DEER CREEK

088462304, Woodbury, IA

Built 1977 Load: 16.5 t ADT: 45

LOCAL

Poor

Over: DRAINAGE DITCH 36

091250302, Wright, IA

Built 1980 Load: 16.5 t ADT: 30

LOCAL

Poor

Over: CREEK

079362501, Audubon, IA

Built 1940 Load: 16.6 t ADT: 5

160TH ST

Poor

Over: QUARTER SECTION RUN CR

092130401, Bremer, IA

Built 1992 Load: 16.6 t ADT: 49

242TH ST.

Poor

Over: UNAMED CREEK

094090607, Fayette, IA

Built 1973 Load: 16.6 t ADT: 148

LOCAL

Poor

Over: CREEK

097172601, Floyd, IA

Built 1956 Load: 16.6 t ADT: 78

LOCAL

Poor

Over: BR MINERVA CREEK

085201802, Marshall, IA

Built 1941 Load: 16.6 t ADT: 40

LOCAL

Poor

Over: BRANCH IOWA RIVER

081140201, Poweshiek, IA

Built 1988 Load: 16.6 t ADT: 60

LOCAL

Poor

Over: FORK NORTH CHARITON

070230402, Wayne, IA

Built 1988 Load: 16.6 t ADT: 20

LOCAL

Poor

Over: MIDDLE RIVER

077320101, Adair, IA

Built 1915 Load: 16.7 t ADT: 29

LOCAL G AVE

Poor

Over: FOUR MILE CREEK

093411802, Cherokee, IA

Built 1976 Load: 16.7 t ADT: 20

LOCAL

Poor

Over: SOUTH RIVER

073271404, Clarke, IA

Built 1900 Load: 16.7 t ADT: 40

FM

Poor

Over: FOX RIVER

069152702, Davis, IA

Built 1955 Load: 16.7 t ADT: 50

LOCAL

Poor

Over: W. FORK BIG CREEK

068273101, Decatur, IA

Built 1970 Load: 16.7 t ADT: 15

LOCAL ROAD

Poor

Over: WOLF CREEK

086180202, Grundy, IA

Built 1970 Load: 16.7 t ADT: 11

LOCAL

Poor

Over: BR BEAVER CREEK

089172802, Grundy, IA

Built 1979 Load: 16.7 t ADT: 15

E 28TH ST S

Poor

Over: SMALL STREAM

079192402, Jasper, IA

Built 1967 Load: 16.7 t ADT: 51

LOC 490TH ST

Poor

Over: W BR BLUE EARTH RIVER

100282101, Kossuth, IA

Built 1980 Load: 16.7 t ADT: 5

LOCAL

Poor

Over: BRANCH SKUNK RIVER

077180403, Marion, IA

Built 1970 Load: 16.7 t ADT: 62

LANCER AVE

Poor

Over: SMALL NATURAL STREAM

099172406, Mitchell, IA

Built 1925 Load: 16.7 t ADT: 1,011

LOCAL

Poor

Over: DRAINAGE

073371904, Montgomery, IA

Built 1987 Load: 16.7 t ADT: 5

FM

Poor

Over: MUD CREEK

078010302, Muscatine, IA

Built 1939 Load: 16.7 t ADT: 50

240TH ST

Poor

Over: BIG WHISKEY SLOUGH

091431401, Plymouth, IA

Built 1953 Load: 16.7 t ADT: 11

LOCAL

Poor

Over: STREAM

079140702, Poweshiek, IA

Built 1956 Load: 16.7 t ADT: 11

FM

Poor

Over: ROCK CREEK

081133101, Poweshiek, IA

Built 1973 Load: 16.7 t ADT: 50

LOCAL

Poor

Over: WALNUT CREEK

069292103, Ringgold, IA

Built 1964 Load: 16.7 t ADT: 11

FM

Poor

Over: S RIVER

075240504, Warren, IA

Built 1949 Load: 16.7 t ADT: 807

GRIMES ST

Poor

Over: BRANCH NORTH RIVER

076250705, Warren, IA

Built 2000 Load: 16.7 t ADT: 15

415TH

Poor

Over: DRAINAGE

099202605, Worth, IA

Built 1900 Load: 16.7 t ADT: 26

LOCAL

Poor

Over: DRAINAGE DITCH 9

091251903, Wright, IA

Built 1920 Load: 16.7 t ADT: 11

APPLE AVENUE

Poor

Over: STREAM

071350704, Adams, IA

Built 1964 Load: 16.8 t ADT: 5

LOCAL

Poor

Over: YELLOW RIVER

096041804, Allamakee, IA

Built 1954 Load: 16.8 t ADT: 128

FM 240 ST

Poor

Over: STREAM

088051701, Delaware, IA

Built 1930 Load: 16.8 t ADT: 79

FM

Poor

Over: ENGLISH RIVER

078093102, Iowa, IA

Built 1957 Load: 16.8 t ADT: 50

FM

Poor

Over: DRAINAGE

071080804, Jefferson, IA

Built 1900 Load: 16.8 t ADT: 50

LOCAL

Poor

Over: STREAM

071091905, Jefferson, IA

Built 1977 Load: 16.8 t ADT: 60

LOCAL

Poor

Over: S FORK ENGLISH RIVER

077130902, Keokuk, IA

Built 1970 Load: 16.8 t ADT: 26

FM 460TH ST

Poor

Over: MIDDLE BRANCH BLUE EARTH

099270601, Kossuth, IA

Built 1967 Load: 16.8 t ADT: 5

FM

Poor

Over: MINERVA CREEK

084201602, Marshall, IA

Built 1916 Load: 16.8 t ADT: 147

LOCAL

Poor

Over: LINN CR

084203602, Marshall, IA

Built 1916 Load: 16.8 t ADT: 157

FM

Poor

Over: LITTLE SIOUX RIVER

085441603, Monona, IA

Built 1961 Load: 16.8 t ADT: 150

Showing 17,501-17,550 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.