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

Fair

Over: STREAM

081153101, Poweshiek, IA

Built 1958 Load: 29.5 t ADT: 11

LOCAL

Fair

Over: SMALL STREAM

094430401, Sioux, IA

Built 1960 Load: 29.5 t ADT: 50

LOCAL

Fair

Over: PLAQUE MINE CREEK

082130906, Tama, IA

Built 1985 Load: 29.5 t ADT: 39

LOCAL

Fair

Over: SMALL

076301201, Adair, IA

Built 1967 Load: 29.6 t ADT: 51

FM

Fair

Over: CREEK

080361304, Audubon, IA

Built 1936 Load: 29.6 t ADT: 71

LOCAL

Fair

Over: SMALL STREAM

084100401, Benton, IA

Built 1991 Load: 29.6 t ADT: 11

E WASHBURN RD

Fair

Over: CEDAR RIVER OVERFLOW

88-12-22-03-10, Black Hawk, IA

Built 2003 Load: 29.6 t ADT: 1,571

FM

Fair

Over: CLINE BRANCH

085E10104, Jackson, IA

Built 1979 Load: 29.6 t ADT: 59

LOCAL

Fair

Over: SMALL STREAM

081213502, Jasper, IA

Built 1996 Load: 29.6 t ADT: 30

COUNTY HOME RD.

Fair

Over: MINERAL CREEK

085023501, Jones, IA

Built 1945 Load: 29.6 t ADT: 26

LOCAL RD

Fair

Over: CROOKED CREEK

076103601, Keokuk, IA

Built 1997 Load: 29.6 t ADT: 40

LOC 510TH ST

Fair

Over: W BR BLUE EARTH RIVER

100280901, Kossuth, IA

Built 1979 Load: 29.6 t ADT: 35

LOC 510TH ST

Fair

Over: MIDDLE BRANCH BLUE EARTH

100281201, Kossuth, IA

Built 1984 Load: 29.6 t ADT: 26

LOCAL

Fair

Over: SMALL STREAM

074041605, Louisa, IA

Built 1986 Load: 29.6 t ADT: 82

US 18

Fair

Over: DRY RUN CREEK

0.7 mi. W of SR A50, Lyon, IA

Built 1975 Load: 29.6 t ADT: 2,240

LOCAL

Fair

Over: DRAINAGE

074280404, Madison, IA

Built 1991 Load: 29.6 t ADT: 15

FM

Fair

Over: DRAINAGE

076270506, Madison, IA

Built 1990 Load: 29.6 t ADT: 89

FM-195TH ST

Fair

Over: KEG CREEK

072433204, Mills, IA

Built 2000 Load: 29.6 t ADT: 240

LOCAL

Fair

Over: OTTER CREEK

083140603, Tama, IA

Built 1940 Load: 29.6 t ADT: 49

FM

Fair

Over: GRAND RIVER

076312502, Adair, IA

Built 1961 Load: 29.7 t ADT: 45

FM

Fair

Over: MIDDLE RIVER

077312003, Adair, IA

Built 1959 Load: 29.7 t ADT: 240

LOCAL

Fair

Over: CREEK

081361502, Audubon, IA

Built 1941 Load: 29.7 t ADT: 21

FM - HIGHLAND

Fair

Over: BUCK CREEK

076360701, Cass, IA

Built 1983 Load: 29.7 t ADT: 89

QUAIL AVE

Fair

Over: CREEK

094202602, Cerro Gordo, IA

Built 1945 Load: 29.7 t ADT: 35

FM

Fair

Over: NORTH WHITE BREAST CREEK

071251204, Clarke, IA

Built 1981 Load: 29.7 t ADT: 15

FM

Fair

Over: EAST LONG CREEK

071273601, Clarke, IA

Built 1982 Load: 29.7 t ADT: 29

225TH ST

Fair

Over: WILLOW CREEK

094360704, Clay, IA

Built 1978 Load: 29.7 t ADT: 26

FM 150TH AVE

Fair

Over: WILLOW CREEK

095382502, Clay, IA

Built 1973 Load: 29.7 t ADT: 180

270TH ST

Fair

Over: STONY CREEK

097380301, Clay, IA

Built 1976 Load: 29.7 t ADT: 26

LOCAL

Fair

Over: BEAMAN CREEK

085371102, Crawford, IA

Built 1951 Load: 29.7 t ADT: 30

170 TH / E26

Fair

Over: WEST BUTTRICKS CREEK

084301101, Greene, IA

Built 1963 Load: 29.7 t ADT: 229

FM

Fair

Over: SOUTH RACCOON RIVER

078300504, Guthrie, IA

Built 1951 Load: 29.7 t ADT: 757

SB IA 1

Fair

Over: RALSTON CREEK

2.5 MI. S OF JCT. I-80, Johnson, IA

Built 1953 Load: 29.7 t ADT: 3,650

W 295TH ST

Fair

Over: RHINE CREEK

080082803, Johnson, IA

Built 1986 Load: 29.7 t ADT: 102

LOCAL

Fair

Over: PLUM CR

081081301, Johnson, IA

Built 1996 Load: 29.7 t ADT: 15

LOCAL

Fair

Over: MUCHAKINOCK CREEK

074161305, Mahaska, IA

Built 1987 Load: 29.7 t ADT: 710

LOCAL

Fair

Over: WHITEBREAST CREEK

074211702, Marion, IA

Built 1986 Load: 29.7 t ADT: 62

FM

Fair

Over: WHIPPOORWILL CREEK

073180705, Monroe, IA

Built 1984 Load: 29.7 t ADT: 60

FM

Fair

Over: STREAM

098411001, Osceola, IA

Built 1974 Load: 29.7 t ADT: 549

NB I-29

Fair

Over: PONY CREEK

2.3 MI. N OF IA 370, Pottawattamie, IA

Built 1968 Load: 29.7 t ADT: 12,100

SB I-29

Fair

Over: PONY CREEK

2.3 MI. N OF IA 370, Pottawattamie, IA

Built 1968 Load: 29.7 t ADT: 12,100

WB I-80

Fair

Over: E BR W NISHNABOTNA RIVER

1.2 MI. E OF JCT. US 59, Pottawattamie, IA

Built 1965 Load: 29.7 t ADT: 11,900

LOCAL

Fair

Over: STREAM

068280503, Ringgold, IA

Built 1932 Load: 29.7 t ADT: 15

LOCAL

Fair

Over: SMALL STREAM

070313501, Ringgold, IA

Built 1920 Load: 29.7 t ADT: 34

IA 130

Fair

Over: E BRANCH MUD CREEK

1.8 mi. E of Jct. SR Y40, Scott, IA

Built 1977 Load: 29.7 t ADT: 1,300

NB US 61

Fair

Over: DME RR

0.8 MI. N OF JCT I-80, Scott, IA

Built 1981 Load: 29.7 t ADT: 18,650

LOCAL

Fair

Over: SMALL CREEK

088471504, Woodbury, IA

Built 1978 Load: 29.7 t ADT: 240

FM

Fair

Over: SHOAL CREEK

067170603, Appanoose, IA

Built 1985 Load: 29.8 t ADT: 45

LOCAL

Fair

Over: CREEK

078351604, Audubon, IA

Built 1969 Load: 29.8 t ADT: 15

LOCAL

Fair

Over: E BR W NISHNABOTNA RIVER

081362502, Audubon, IA

Built 1986 Load: 29.8 t ADT: 41

Showing 5,301-5,350 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.