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

069100305, Van Buren, IA

Built 1955 Load: 14.3 t ADT: 41

LOCAL

Poor

Over: UPPER IOWA RIVER

099073607, Winneshiek, IA

Built 1900 Load: 14.3 t ADT: 49

LOCAL - UPLAND

Poor

Over: SEVEN MILE CREEK

074361701, Cass, IA

Built 1976 Load: 14.4 t ADT: 15

FM

Poor

Over: LONG BRANCH

078302601, Guthrie, IA

Built 1978 Load: 14.4 t ADT: 34

LOCAL

Poor

Over: BIG MILL CREEK

086E40705, Jackson, IA

Built 1986 Load: 14.4 t ADT: 15

LOCAL RD

Poor

Over: JIM CREEK

077292002, Madison, IA

Built 1961 Load: 14.4 t ADT: 34

LOCAL

Poor

Over: BRANCH N SKUNK RIVER

082200303, Marshall, IA

Built 1910 Load: 14.4 t ADT: 82

240TH ST

Poor

Over: CREEK

079E11503, Scott, IA

Built 1965 Load: 14.4 t ADT: 31

LOCAL

Poor

Over: WHISKEY CREEK

076063304, Washington, IA

Built 1917 Load: 14.4 t ADT: 60

LOCAL

Poor

Over: PINE CREEK

099091004, Winneshiek, IA

Built 1938 Load: 14.4 t ADT: 118

LOCAL - HAMBURG

Poor

Over: TURKEY CREEK

076350903, Cass, IA

Built 1974 Load: 14.5 t ADT: 62

FM

Poor

Over: WELDON RIVER

067241005, Decatur, IA

Built 1958 Load: 14.5 t ADT: 379

LOCAL

Poor

Over: SEVEN MILE CREEK

067271401, Decatur, IA

Built 1963 Load: 14.5 t ADT: 103

US 69

Poor

Over: ZADIE CREEK

0.9 mi. W. of Jct. I-35, Decatur, IA

Built 1925 Load: 14.5 t ADT: 610

FM NE RPD CK RD

Poor

Over: BR RAPID CR

080052105, Johnson, IA

Built 1950 Load: 14.5 t ADT: 130

LOC 120TH ST

Poor

Over: PRAIRIE CREEK

095272601, Kossuth, IA

Built 1988 Load: 14.5 t ADT: 26

LOCAL

Poor

Over: STREAM

073043102, Louisa, IA

Built 1915 Load: 14.5 t ADT: 21

FM

Poor

Over: DRAINAGE

074271003, Madison, IA

Built 1951 Load: 14.5 t ADT: 40

LOCAL

Poor

Over: MUD CREEK

085192104, Marshall, IA

Built 1946 Load: 14.5 t ADT: 41

LOCAL

Poor

Over: BEAR CREEK

080140702, Poweshiek, IA

Built 1950 Load: 14.5 t ADT: 60

710TH AVE

Poor

Over: MIDDLE MINERVA CREEK

085212204, Story, IA

Built 1953 Load: 14.5 t ADT: 60

LOCAL

Poor

Over: BRANCH FLANK CREEK

074221002, Warren, IA

Built 1965 Load: 14.5 t ADT: 46

FM

Poor

Over: WOLF CREEK

074221202, Warren, IA

Built 1955 Load: 14.5 t ADT: 110

LOCAL - JASPER

Poor

Over: NISHNABOTNA RIVER

076372303, Cass, IA

Built 1959 Load: 14.6 t ADT: 46

CRYSTAL RD

Poor

Over: STREAM

092061104, Clayton, IA

Built 1920 Load: 14.6 t ADT: 44

LOCAL

Poor

Over: ZADIE CREEK

067271502, Decatur, IA

Built 1964 Load: 14.6 t ADT: 72

LOCAL

Poor

Over: STREAM

069252506, Decatur, IA

Built 1961 Load: 14.6 t ADT: 41

LOCAL

Poor

Over: STREAM

069270501, Decatur, IA

Built 1961 Load: 14.6 t ADT: 21

LOCAL

Poor

Over: CREEK

086241001, Hamilton, IA

Built 1918 Load: 14.6 t ADT: 131

MOBILE AVE

Poor

Over: ALLEN CREEK

081433402, Harrison, IA

Built 1957 Load: 14.6 t ADT: 11

LOCAL

Poor

Over: ROCK CR

084172701, Marshall, IA

Built 1942 Load: 14.6 t ADT: 62

LOCAL RD

Poor

Over: LOTTS CREEK

068292503, Ringgold, IA

Built 1900 Load: 14.6 t ADT: 20

UNITY AVENUE

Poor

Over: BRANCH OF SILVER CREEK

099110902, Howard, IA

Built 1960 Load: 14.7 t ADT: 21

LOCAL

Poor

Over: SMALL STREAM

073042105, Louisa, IA

Built 1930 Load: 14.7 t ADT: 11

A26 (180TH ST)

Poor

Over: BIG SIOUX RIVER

099482103, Lyon, IA

Built 1977 Load: 14.7 t ADT: 1,017

LOCAL

Poor

Over: LIZARD CREEK

094342502, Palo Alto, IA

Built 1921 Load: 14.7 t ADT: 21

320TH ST

Poor

Over: CREEK

090442701, Plymouth, IA

Built 1900 Load: 14.7 t ADT: 30

LYNX AVE

Poor

Over: BIG WHISKEY CREEK

090450402, Plymouth, IA

Built 1958 Load: 14.7 t ADT: 50

220TH ST

Poor

Over: DRAINAGE

091450501, Plymouth, IA

Built 1958 Load: 14.7 t ADT: 26

200TH ST

Poor

Over: PLYMOUTH CREEK

092443001, Plymouth, IA

Built 1952 Load: 14.7 t ADT: 15

200TH ST

Poor

Over: DRAINAGE

092492603, Plymouth, IA

Built 1959 Load: 14.7 t ADT: 30

FM

Poor

Over: MUD CREEK

074413602, Pottawattamie, IA

Built 1976 Load: 14.7 t ADT: 20

220TH STREET

Poor

Over: PIGEON CREEK

077432602, Pottawattamie, IA

Built 1925 Load: 14.7 t ADT: 5

LOCAL

Poor

Over: BEAR CREEK

080141304, Poweshiek, IA

Built 1935 Load: 14.7 t ADT: 26

305TH ST

Poor

Over: STREAM

080E31205, Scott, IA

Built 1976 Load: 14.7 t ADT: 143

LOCAL

Poor

Over: SMALL STREAM

071293502, Union, IA

Built 1973 Load: 14.7 t ADT: 15

POCAHONTAS AVE

Poor

Over: STREAM

087421702, Woodbury, IA

Built 1935 Load: 14.7 t ADT: 5

FM

Poor

Over: CRANE CREEK

096111903, Chickasaw, IA

Built 1959 Load: 14.8 t ADT: 157

LOCAL

Poor

Over: DUGOUT CREEK

099380701, Dickinson, IA

Built 1967 Load: 14.8 t ADT: 11

LOCAL

Poor

Over: LITTLEFLOOD CREEK

095172501, Floyd, IA

Built 1987 Load: 14.8 t ADT: 29

Showing 17,201-17,250 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.