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: LIME CREEK

087102603, Buchanan, IA

Built 1954 Load: 12.6 t ADT: 80

WREN

Fair

Over: WINNEBAGO RIVER

096193504, Cerro Gordo, IA

Built 1935 Load: 12.6 t ADT: 30

LOCAL

Fair

Over: EAST SOLDIER RIVER

084400902, Crawford, IA

Built 1945 Load: 12.6 t ADT: 30

LOCAL

Fair

Over: LINN CREEK

083190501, Marshall, IA

Built 1939 Load: 12.6 t ADT: 21

IA 175

Fair

Over: STREAM

0.1 mi. W of jct. SR M64, Sac, IA

Built 1937 Load: 12.6 t ADT: 1,930

LOCAL

Fair

Over: HILTON CREEK

080100804, Iowa, IA

Built 1986 Load: 12.7 t ADT: 34

710TH AVE

Fair

Over: DRAINAGE

083213402, Story, IA

Built 1959 Load: 12.7 t ADT: 11

270TH ST

Fair

Over: GRANT 5 OPEN DITCH

083233601, Story, IA

Built 1944 Load: 12.7 t ADT: 40

180TH ST

Fair

Over: EAST BR INDIAN CREEK

084221301, Story, IA

Built 1955 Load: 12.7 t ADT: 40

610TH AVE

Fair

Over: WEST BR INDIAN CREEK

084232402, Story, IA

Built 1911 Load: 12.7 t ADT: 34

LOCAL

Fair

Over: PLATTE BRANCH

068323201, Taylor, IA

Built 1945 Load: 12.7 t ADT: 5

LOCAL ROAD

Fair

Over: BRANCH FLANK CREEK

074220301, Warren, IA

Built 1960 Load: 12.7 t ADT: 26

WALNUT AVENUE

Fair

Over: E FORK E NODAWAY RIVER

073322604, Adams, IA

Built 1979 Load: 12.8 t ADT: 71

FM

Fair

Over: BRUSHY CREEK

080321404, Guthrie, IA

Built 1976 Load: 12.8 t ADT: 26

FM

Fair

Over: IOWA RIVER

082140406, Tama, IA

Built 1941 Load: 12.8 t ADT: 59

LOCAL

Fair

Over: CREEK

079340805, Audubon, IA

Built 1900 Load: 12.9 t ADT: 11

FM

Fair

Over: NORTH RIVER

077293102, Madison, IA

Built 1930 Load: 12.9 t ADT: 50

LOCAL

Fair

Over: DRAINAGE

071182103, Monroe, IA

Built 1993 Load: 12.9 t ADT: 40

LOCAL

Fair

Over: MILL CREEK

094410301, O'Brien, IA

Built 1924 Load: 12.9 t ADT: 35

IRONWOOD AVE

Fair

Over: BUCK CREEK

068382106, Page, IA

Built 1982 Load: 12.9 t ADT: 34

LOCAL

Fair

Over: E NISHNABOTNA RIVER

079350201, Audubon, IA

Built 1924 Load: 13.0 t ADT: 15

FM 140TH ST

Fair

Over: SMALL STREAM

090092701, Buchanan, IA

Built 1958 Load: 13.0 t ADT: 147

FM

Fair

Over: CREEK

072081903, Jefferson, IA

Built 1948 Load: 13.0 t ADT: 25

LOCAL

Fair

Over: ROCK CR

084172201, Marshall, IA

Built 1950 Load: 13.0 t ADT: 5

LOCAL

Fair

Over: WILLOW CREEK

081391401, Shelby, IA

Built 1955 Load: 13.0 t ADT: 26

LOCAL

Fair

Over: SMALL STREAM

081403603, Shelby, IA

Built 1950 Load: 13.0 t ADT: 30

LOCAL

Fair

Over: BR LONG CREEK

071273504, Clarke, IA

Built 1900 Load: 13.1 t ADT: 20

IA 15

Fair

Over: PILOT CREEK

At the N jct. of SR C26, Pocahontas, IA

Built 1957 Load: 13.1 t ADT: 510

FM

Fair

Over: DD #31

087353403, Sac, IA

Built 1919 Load: 13.1 t ADT: 34

M68 DELTA AVE

Fair

Over: FIELD STREAM

082362202, Carroll, IA

Built 1952 Load: 13.2 t ADT: 100

LOCAL

Fair

Over: EAST SOLDIER RIVER

084400804, Crawford, IA

Built 1940 Load: 13.2 t ADT: 11

LOCAL

Fair

Over: SKUNK RIVER

087242405, Hamilton, IA

Built 1952 Load: 13.2 t ADT: 90

290TH ST

Fair

Over: CREEK

086191101, Hardin, IA

Built 2000 Load: 13.2 t ADT: 69

FM

Fair

Over: SMALL

081090801, Iowa, IA

Built 1949 Load: 13.2 t ADT: 130

MAGNOLIA ROAD

Fair

Over: SILVER CREEK

076402101, Pottawattamie, IA

Built 1946 Load: 13.2 t ADT: 5

LOCAL

Fair

Over: KEG CREEK

079391801, Shelby, IA

Built 1992 Load: 13.2 t ADT: 15

LOCAL

Fair

Over: SNAKE CREEK

081381702, Shelby, IA

Built 1995 Load: 13.2 t ADT: 21

FM LAWRENCE AVE

Fair

Over: SMALL STREAM

090091302, Buchanan, IA

Built 1953 Load: 13.3 t ADT: 41

KLAREN RD

Fair

Over: CREEK

087021601, Dubuque, IA

Built 1941 Load: 13.3 t ADT: 5

FM

Fair

Over: MAQUOKETA RIVER

084E50404, Jackson, IA

Built 1956 Load: 13.3 t ADT: 610

LOCAL ROAD

Fair

Over: MUD CREEK

098462701, Lyon, IA

Built 1962 Load: 13.3 t ADT: 62

LOCAL

Fair

Over: BIG INDIAN CR

068102402, Van Buren, IA

Built 1969 Load: 13.3 t ADT: 62

LOCAL

Fair

Over: BUTTRICK CREEK

086280702, Webster, IA

Built 1913 Load: 13.3 t ADT: 26

FM

Fair

Over: FIELD STREAM

082360601, Carroll, IA

Built 1962 Load: 13.4 t ADT: 89

LOCAL

Fair

Over: HAY CREEK

083370703, Crawford, IA

Built 1999 Load: 13.4 t ADT: 11

ANAMOSA REFORM

Fair

Over: BUFFALO CREEK

IN QUARRY at ST. REFORM., Jones, IA

Built 1900 Load: 13.4 t

CUMMINGS FD.RD.

Fair

Over: W OTTER CR

085082411, Linn, IA

Built 1956 Load: 13.4 t ADT: 70

270TH ST

Fair

Over: CREEK

079353101, Audubon, IA

Built 1957 Load: 13.5 t ADT: 20

LOCAL

Fair

Over: UNNAMED CREEK

080360705, Audubon, IA

Built 1967 Load: 13.5 t ADT: 15

W AVE

Fair

Over: LOCAL STREAM

082392901, Crawford, IA

Built 1960 Load: 13.5 t ADT: 5

Showing 1,251-1,300 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.