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

M AVENUE

Poor

Over: STREAM

069370802, Page, IA

Built 1900 Load: 10.2 t ADT: 11

LOCAL

Poor

Over: COATES CR

069081701, Van Buren, IA

Built 1959 Load: 10.2 t ADT: 11

LOCAL

Poor

Over: CREEK

088462901, Woodbury, IA

Built 1950 Load: 10.2 t ADT: 60

E 40TH ST S

Poor

Over: REASNOR CREEK

078190102, Jasper, IA

Built 1978 Load: 10.3 t ADT: 41

LOCAL

Poor

Over: CREEK

069340707, Taylor, IA

Built 1978 Load: 10.3 t ADT: 29

LOCAL

Poor

Over: VILLAGE CREEK

071141302, Wapello, IA

Built 2000 Load: 10.3 t ADT: 30

LOCAL

Poor

Over: KNACK CREEK

086270704, Webster, IA

Built 1915 Load: 10.3 t ADT: 46

LOCAL

Poor

Over: ROCK CREEK

086111801, Benton, IA

Built 1982 Load: 10.4 t ADT: 26

LOCAL- F AVE

Poor

Over: SMALL CREEK

090423602, Cherokee, IA

Built 1919 Load: 10.4 t ADT: 30

LOCAL

Poor

Over: DM RIVER

093280602, Humboldt, IA

Built 1900 Load: 10.4 t ADT: 11

LOCAL

Poor

Over: PRAIRIE CREEK

084E23602, Jackson, IA

Built 1971 Load: 10.4 t ADT: 130

LOCAL

Poor

Over: EAST 102 RIVER

068330809, Taylor, IA

Built 1971 Load: 10.4 t ADT: 20

LOCAL

Poor

Over: STREAM

087442403, Woodbury, IA

Built 1950 Load: 10.4 t ADT: 5

LOCAL

Poor

Over: WRIGHT CREEK

088433603, Woodbury, IA

Built 1900 Load: 10.4 t ADT: 20

160TH ST

Poor

Over: BEAVER CREEK

084280401, Boone, IA

Built 1915 Load: 10.5 t ADT: 5

LOCAL-490TH ST

Poor

Over: MAPLE RIVER

092391201, Cherokee, IA

Built 1900 Load: 10.5 t ADT: 40

FM

Poor

Over: SOAP CREEK

070131204, Davis, IA

Built 1956 Load: 10.5 t ADT: 640

LOCAL ROAD

Poor

Over: BRANCH SUGAR CREEK

073072807, Henry, IA

Built 1922 Load: 10.5 t ADT: 26

300TH ST

Poor

Over: JOHN'S CREEK

090441301, Plymouth, IA

Built 1900 Load: 10.5 t ADT: 26

LOCAL

Poor

Over: CREEK

079361108, Audubon, IA

Built 1956 Load: 10.6 t ADT: 26

LOCAL - QUINCY

Poor

Over: WATERWAY

075342801, Cass, IA

Built 1967 Load: 10.6 t ADT: 30

LOCAL

Poor

Over: SMALL STREAM

072242502, Clarke, IA

Built 1900 Load: 10.6 t ADT: 11

1550 210TH ST

Poor

Over: DRAINAGE DITCH 6

095240901, Hancock, IA

Built 1968 Load: 10.6 t ADT: 259

260TH

Poor

Over: JOHN'S CREEK

091442601, Plymouth, IA

Built 1966 Load: 10.6 t ADT: 11

LOCAL

Poor

Over: SOUTH RIVER

073260704, Clarke, IA

Built 1983 Load: 10.7 t ADT: 5

LOCAL

Poor

Over: W FK W NISHNABOTNA RIVER

082370602, Crawford, IA

Built 1949 Load: 10.7 t ADT: 35

LOCAL

Poor

Over: SMALL STREAM

079101307, Iowa, IA

Built 1984 Load: 10.7 t ADT: 71

FM

Poor

Over: MAQUOKETA RIVER

084E10104, Jackson, IA

Built 1927 Load: 10.7 t ADT: 50

LOCAL

Poor

Over: DRAINAGE

076280904, Madison, IA

Built 1939 Load: 10.7 t ADT: 34

170TH ST

Poor

Over: DRAINAGE

092460801, Plymouth, IA

Built 1900 Load: 10.7 t ADT: 34

LOCAL ROAD

Poor

Over: FLANK CREEK

075223301, Warren, IA

Built 1965 Load: 10.7 t ADT: 30

LOCAL

Poor

Over: STREAM

078330103, Guthrie, IA

Built 1930 Load: 10.8 t ADT: 5

LOCAL

Poor

Over: TILTON CREEK

088223102, Hardin, IA

Built 1981 Load: 10.8 t ADT: 26

JASPER TRAIL

Poor

Over: SMALL CREEK

079441103, Harrison, IA

Built 1900 Load: 10.8 t ADT: 50

FM LOU FALL RD

Poor

Over: BR IOWA RIVER

081072103, Johnson, IA

Built 1956 Load: 10.8 t ADT: 265

LOCAL

Poor

Over: LINN CREEK

084202502, Marshall, IA

Built 1919 Load: 10.8 t ADT: 30

LOCAL

Poor

Over: LOCAL STREAM

082432208, Monona, IA

Built 1900 Load: 10.8 t ADT: 11

310TH ST

Poor

Over: DRY BRANCH

090441901, Plymouth, IA

Built 1941 Load: 10.8 t ADT: 26

FM K-42

Poor

Over: CARTER CREEK

090460202, Plymouth, IA

Built 1941 Load: 10.8 t ADT: 190

LOCAL

Poor

Over: DEEP CREEK

093431001, Plymouth, IA

Built 1941 Load: 10.8 t ADT: 11

160TH

Poor

Over: BEAVER DAM CREEK

094210101, Cerro Gordo, IA

Built 1913 Load: 10.9 t ADT: 30

LOCAL

Poor

Over: SOLDIER RIVER

085411102, Crawford, IA

Built 1951 Load: 10.9 t ADT: 41

FM

Poor

Over: CEDAR RIVER

097172405, Floyd, IA

Built 1936 Load: 10.9 t ADT: 79

LOCAL

Poor

Over: BOONE RIVER

087261604, Hamilton, IA

Built 1954 Load: 10.9 t ADT: 60

LOCAL

Poor

Over: STREAM

099413302, Osceola, IA

Built 1944 Load: 10.9 t ADT: 21

LOCAL 570TH ST

Poor

Over: MAPLE RIVER

091392001, Cherokee, IA

Built 1918 Load: 11.0 t ADT: 11

JUNE AVE

Poor

Over: SMALL STREAM

091030710, Clayton, IA

Built 1910 Load: 11.0 t ADT: 21

295TH ST

Poor

Over: STREAM

092051203, Clayton, IA

Built 1910 Load: 11.0 t ADT: 51

LOCAL

Poor

Over: BROWN CREEK

099330603, Emmet, IA

Built 1972 Load: 11.0 t ADT: 34

FAWN AVE

Poor

Over: DRAINAGE

092470802, Plymouth, IA

Built 1900 Load: 11.0 t ADT: 30

Showing 16,851-16,900 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.