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: SMALL STREAM

089382802, Sac, IA

Built 1931 Load: 11.0 t ADT: 20

LOCAL

Poor

Over: STREAM

070100504, Van Buren, IA

Built 1968 Load: 11.0 t ADT: 25

LOCAL

Poor

Over: JIM CREEK

077291302, Madison, IA

Built 1939 Load: 11.1 t ADT: 11

FM

Poor

Over: NE NORWAY CREEK

083422602, Monona, IA

Built 1949 Load: 11.1 t ADT: 50

LOCAL

Poor

Over: NODAWAY RIVER

072362904, Montgomery, IA

Built 1968 Load: 11.1 t ADT: 20

LOCAL

Poor

Over: LITTLE OCHEYEDAN RIVER

099403302, Osceola, IA

Built 1934 Load: 11.1 t ADT: 21

200TH ST

Poor

Over: W.BRANCH FLOYD RIVER

092462603, Plymouth, IA

Built 1960 Load: 11.1 t ADT: 71

LOCAL

Poor

Over: MIDDLE NODAWAY RIVER BR

074330104, Adair, IA

Built 1949 Load: 11.2 t ADT: 15

FM

Poor

Over: WAPSIPINICON RIVER

096140901, Chickasaw, IA

Built 1957 Load: 11.2 t ADT: 501

LOCAL

Poor

Over: N CEDAR CREEK

074192704, Marion, IA

Built 1994 Load: 11.2 t ADT: 11

FM

Poor

Over: SOUTH TIMBER CREEK

083173204, Marshall, IA

Built 1942 Load: 11.2 t ADT: 88

LOCAL

Poor

Over: TIMBER CREEK

083182405, Marshall, IA

Built 1942 Load: 11.2 t ADT: 91

LOCAL

Poor

Over: DD6

095340901, Palo Alto, IA

Built 1917 Load: 11.2 t ADT: 11

632ND AVE

Poor

Over: STREAM

082220806, Story, IA

Built 1973 Load: 11.2 t ADT: 60

LOCAL

Poor

Over: SALT CREEK

082130105, Tama, IA

Built 1982 Load: 11.2 t ADT: 11

LOC B LEVEL RD

Poor

Over: STREAM

073311401, Union, IA

Built 1940 Load: 11.2 t ADT: 21

FM

Poor

Over: BR W PLATTE RIVER

073312502, Union, IA

Built 1957 Load: 11.2 t ADT: 788

LOCAL

Poor

Over: DAVIS CREEK

076071502, Washington, IA

Built 1980 Load: 11.2 t ADT: 11

FM

Poor

Over: MID FK MEDICINE RIVER

067221405, Wayne, IA

Built 1980 Load: 11.2 t ADT: 15

LOCAL

Poor

Over: W FK W NISHNABOTNA RIVER

082383302, Crawford, IA

Built 1944 Load: 11.3 t ADT: 46

FM

Poor

Over: SHANE CREEK

067272003, Decatur, IA

Built 1950 Load: 11.3 t ADT: 50

OTTER RD.

Poor

Over: CREEK

095093404, Fayette, IA

Built 1966 Load: 11.3 t ADT: 29

FM

Poor

Over: IOWA RIVER

085192707, Marshall, IA

Built 1952 Load: 11.3 t ADT: 49

LOCAL

Poor

Over: MINOR DRAINAGE

073391802, Montgomery, IA

Built 1966 Load: 11.3 t ADT: 5

EVERGREEN AVE

Poor

Over: DRAINAGE

091471902, Plymouth, IA

Built 1900 Load: 11.3 t ADT: 11

LOCAL

Poor

Over: DUCK VALLEY

070212306, Wayne, IA

Built 1978 Load: 11.3 t ADT: 5

LOCAL

Poor

Over: OTTER CREEK

092262105, Wright, IA

Built 1967 Load: 11.3 t ADT: 31

FM

Poor

Over: CHARITON RIVER

068172607, Appanoose, IA

Built 1957 Load: 11.4 t ADT: 40

LOCAL

Poor

Over: STREAM

071272103, Clarke, IA

Built 1977 Load: 11.4 t ADT: 11

LOCAL

Poor

Over: BEAVER CREEK

078310204, Guthrie, IA

Built 1920 Load: 11.4 t ADT: 11

LOCAL

Poor

Over: HONEY BRANCH CREEK

072111904, Jefferson, IA

Built 1918 Load: 11.4 t ADT: 20

LOCAL

Poor

Over: S FORK ENGLISH RIVER

077122402, Keokuk, IA

Built 1953 Load: 11.4 t ADT: 34

LOCAL

Poor

Over: OTTER CR

073040103, Louisa, IA

Built 1921 Load: 11.4 t ADT: 16

FM

Poor

Over: GRAND RIVER

074292704, Madison, IA

Built 1957 Load: 11.4 t ADT: 131

LONE TREE RD

Poor

Over: PERRY CREEK

090472205, Plymouth, IA

Built 1953 Load: 11.4 t ADT: 71

120TH ST

Poor

Over: INDIAN CREEK

093471801, Plymouth, IA

Built 1900 Load: 11.4 t ADT: 15

LOCAL

Poor

Over: WILLOW CREEK

083411602, Crawford, IA

Built 1961 Load: 11.5 t ADT: 35

FM

Poor

Over: BIG BEAR CREEK

081162702, Poweshiek, IA

Built 1955 Load: 11.5 t ADT: 60

LOCAL

Poor

Over: CEDAR CREEK

076141203, Mahaska, IA

Built 1973 Load: 11.6 t ADT: 26

LOCAL

Poor

Over: DRAINAGE

073161506, Monroe, IA

Built 1956 Load: 11.6 t ADT: 20

FM

Poor

Over: BUSHY CREEK

068352507, Taylor, IA

Built 1955 Load: 11.6 t ADT: 40

FM

Poor

Over: COMSTOCK CREEK

073143001, Wapello, IA

Built 1991 Load: 11.6 t ADT: 40

LOCAL

Poor

Over: MIDDLE RIVER

076251410, Warren, IA

Built 1950 Load: 11.6 t ADT: 72

270TH ST

Poor

Over: CREEK

079353101, Audubon, IA

Built 1959 Load: 11.7 t ADT: 20

LOCAL

Poor

Over: FIELD STREAM

084340404, Carroll, IA

Built 1913 Load: 11.7 t ADT: 26

LOCAL 580TH ST.

Poor

Over: ROCK CREEK

091412801, Cherokee, IA

Built 1917 Load: 11.7 t ADT: 5

LOCAL B AVE.

Poor

Over: FIDDLE CREEK

091421702, Cherokee, IA

Built 1915 Load: 11.7 t ADT: 20

LOCAL580TH ST

Poor

Over: FIDDLE CREEK

091423001, Cherokee, IA

Built 1917 Load: 11.7 t ADT: 5

HORNET RD

Poor

Over: BEAR CREEK

092043303, Clayton, IA

Built 1923 Load: 11.7 t ADT: 73

LOCAL

Poor

Over: TIPTON CREEK

087220302, Hardin, IA

Built 1987 Load: 11.7 t ADT: 16

Showing 16,901-16,950 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.