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: STREAM

076310404, Adair, IA

Built 1954 ADT: 11

FM

Poor

Over: CHARITON RIVER

068171303, Appanoose, IA

Built 1959 ADT: 50

LOCAL

Poor

Over: CREEK

079341603, Audubon, IA

Built 1932 ADT: 15

RICE RD

Poor

Over: TRIB TO WAPSIPINICON RVR

90-11-35-04-10, Black Hawk, IA

Built 1940 ADT: 44

FM

Poor

Over: EAST SOLDIER RIVER

084411302, Crawford, IA

Built 1960 ADT: 499

FM

Poor

Over: STREAM

067261004, Decatur, IA

Built 1971 ADT: 79

LOCAL RD

Poor

Over: WOLF CREEK

070261104, Decatur, IA

Built 1978 ADT: 35

310 AVENUE

Poor

Over: BRUSH CREEK

070412004, Fremont, IA

Built 1900 ADT: 41

LOCAL LEGNO

Poor

Over: STREAM

087262904, Hamilton, IA

Built 1920

FM

Poor

Over: HONEY CREEK

086200809, Hardin, IA

Built 1985 ADT: 59

LOCAL

Poor

Over: SMALL STREAM

087191403, Hardin, IA

Built 1987 ADT: 20

LOCAL

Poor

Over: TIPTON CREEK

087202105, Hardin, IA

Built 1900 ADT: 20

LOCAL

Poor

Over: HONEY CREEK

087213101, Hardin, IA

Built 1986 ADT: 26

LOCAL

Poor

Over: BEAVER CREEK

088202103, Hardin, IA

Built 1984 ADT: 39

LOCAL

Poor

Over: BRANCH FISH CREEK

070061605, Henry, IA

Built 1974 ADT: 35

STONE BRIDGE RD

Poor

Over: WET CREEK

086031704, Jones, IA

Built 1893 ADT: 294

FM 160TH ST

Poor

Over: LOTTS CREEK

094300501, Kossuth, IA

Built 1967 ADT: 45

FM

Poor

Over: LOST CREEK

068040404, Lee, IA

Built 1953 ADT: 1,310

FM

Poor

Over: MIDDLE RIVER

076262908, Madison, IA

Built 1958 ADT: 300

FM

Poor

Over: CEDAR CREEK

074141902, Mahaska, IA

Built 1963 ADT: 470

LOCAL

Poor

Over: DRAINAGE DITCH #2

075163306, Mahaska, IA

Built 1900 ADT: 11

FM

Poor

Over: BNSF RR AND STREAM

075190306, Marion, IA

Built 1964 ADT: 2,620

94TH PLACE

Poor

Over: TRACEY CREEK

075202804, Marion, IA

Built 1958 ADT: 40

FM

Poor

Over: SOUTH TIMBER CREEK

083172801, Marshall, IA

Built 1954 ADT: 59

LOCAL

Poor

Over: BURNETT CR

084170402, Marshall, IA

Built 1917 ADT: 5

LOCAL

Poor

Over: BR MINERVA CR

085200502, Marshall, IA

Built 1919 ADT: 30

LOCAL

Poor

Over: CREEK

077012704, Muscatine, IA

Built 1956 ADT: 35

LOCAL ROAD

Poor

Over: FOUR MILE CREEK

080233005, Polk, IA

Built 1941 ADT: 89

LOCAL

Poor

Over: SUGAR CREEK

079162003, Poweshiek, IA

Built 1923 ADT: 50

85TH AVE

Poor

Over: CREEK

079E20906, Scott, IA

Built 1974 ADT: 102

675TH AVE

Poor

Over: ROCK CREEK

082221304, Story, IA

Built 1911 ADT: 20

325TH ST

Poor

Over: SMALL STREAM

082222605, Story, IA

Built 1905 ADT: 34

597TH AVE

Poor

Over: SMALL STREAM

082232206, Story, IA

Built 1974 ADT: 30

FM

Poor

Over: BRANCH IOWA RIVER

084160302, Tama, IA

Built 1969 ADT: 579

LOCAL

Poor

Over: WOLF CREEK

073122905, Wapello, IA

Built 1965 ADT: 62

UNDERWOOD AVE

Poor

Over: N FORK LONG CR

075061602, Washington, IA

Built 1953 ADT: 131

FM

Poor

Over: DRAINAGE

089270702, Webster, IA

Built 1977 ADT: 359

FM

Poor

Over: DRAINAGE DITCH NO 3

090300801, Webster, IA

Built 1980 ADT: 15

LOCAL ROAD

Poor

Over: CREEK

100091403, Winneshiek, IA

Built 1900 ADT: 29

FM

Poor

Over: PIERSON CREEK

089420901, Woodbury, IA

Built 1956 ADT: 199

LOCAL

Poor

Over: CREEK

078342601, Audubon, IA

Built 1935 Load: 2.7 t ADT: 21

LOCAL

Poor

Over: BR WHITEBREAST CREEK

073223305, Lucas, IA

Built 1966 Load: 2.7 t ADT: 62

LOCAL

Poor

Over: DRAINAGE

074292703, Madison, IA

Built 1958 Load: 2.7 t ADT: 11

LOCAL ROAD

Poor

Over: BOHEMIAN CREEK

097101502, Winneshiek, IA

Built 1962 Load: 2.7 t ADT: 88

110TH STREET

Poor

Over: STREAM

070381101, Page, IA

Built 1953 Load: 3.1 t ADT: 20

Ag and DNR Traffic

Poor

Over: Prairie Creek

Marion Co., S20,T77N,R20, Marion, IA

Built 1952 Load: 3.2 t ADT: 1

632ND AVE

Poor

Over: WEST BR INDIAN CREEK

082220806, Story, IA

Built 1938 Load: 3.2 t ADT: 60

FM

Poor

Over: LITTLE BEAVER CREEK

082273302, Boone, IA

Built 1973 Load: 3.3 t ADT: 45

LOCAL

Poor

Over: MIDDLE TIMBER CREEK

083182604, Marshall, IA

Built 1916 Load: 3.3 t ADT: 51

FM - JACKSON

Poor

Over: WATERWAY

076361406, Cass, IA

Built 1985 Load: 3.4 t ADT: 139

Showing 16,601-16,650 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.