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

230TH STREET

Fair

Over: OTTER CREEK

093212401, Franklin, IA

Built 1957 Load: 25.1 t ADT: 41

KILLDEER AVE

Fair

Over: DRAINAGE DITCH NO 55

093212602, Franklin, IA

Built 1955 Load: 25.1 t ADT: 21

NEW ORLEANS A

Fair

Over: THOMAS DITCH

000000000, Fremont, IA

Built 1957 Load: 25.1 t ADT: 377

IA 2

Fair

Over: FISHER CREEK

2.1 mi. W of jct. US 59, Fremont, IA

Built 1975 Load: 25.1 t ADT: 1,910

WB US 20

Fair

Over: BOONE RIVER/REC TRAIL

1.2 MI E OF E JCT IA 17, Hamilton, IA

Built 1974 Load: 25.1 t ADT: 5,050

1320 150TH ST

Fair

Over: WEST IOWA RIVER

094240801, Hancock, IA

Built 1956 Load: 25.1 t ADT: 31

1280 320TH ST

Fair

Over: DD 1&2

097251301, Hancock, IA

Built 1956 Load: 25.1 t ADT: 63

LOCAL

Fair

Over: CREEK

086211204, Hardin, IA

Built 1956 Load: 25.1 t ADT: 41

LOCAL

Fair

Over: IOWA RIVER

088200205, Hardin, IA

Built 1983 Load: 25.1 t ADT: 41

FM - 305TH ST

Fair

Over: MOSQUITO CREEK

078411603, Harrison, IA

Built 1978 Load: 25.1 t ADT: 34

FM 296TH ST

Fair

Over: PIGEON CREEK

078421101, Harrison, IA

Built 1962 Load: 25.1 t ADT: 270

SEWARD AVE

Fair

Over: PIGEON CREEK

078423304, Harrison, IA

Built 1979 Load: 25.1 t ADT: 60

FM

Fair

Over: MAPLE RIVER

088403503, Ida, IA

Built 1981 Load: 25.1 t ADT: 40

SW OBSERVTY AVE

Fair

Over: OLD MANS CREEK

078062105, Johnson, IA

Built 1980 Load: 25.1 t ADT: 290

FM

Fair

Over: STREAM

074121804, Keokuk, IA

Built 1957 Load: 25.1 t ADT: 45

FM

Fair

Over: SMALL STREAM

073022905, Louisa, IA

Built 1959 Load: 25.1 t ADT: 440

IA 92

Fair

Over: MIDDLE RIVER

2.0 mi. W of SR P-53, Madison, IA

Built 1967 Load: 25.1 t ADT: 1,130

LOCAL

Fair

Over: SMALL STREAM

074271607, Madison, IA

Built 1986 Load: 25.1 t ADT: 45

LOCAL

Fair

Over: LAKE

082200602, Marshall, IA

Built 1968 Load: 25.1 t ADT: 50

FM

Fair

Over: MINERVA CREEK

084190506, Marshall, IA

Built 1982 Load: 25.1 t ADT: 255

LOCAL

Fair

Over: MUD CREEK

085201304, Marshall, IA

Built 1957 Load: 25.1 t ADT: 11

FM

Fair

Over: INDIAN CREEK

073390302, Montgomery, IA

Built 1957 Load: 25.1 t ADT: 45

LOCAL

Fair

Over: INDIAN CREEK

073392001, Montgomery, IA

Built 1956 Load: 25.1 t ADT: 29

US 59

Fair

Over: BRANCH FLOYD RIVER

1.9 mi. N of N jct. US 18, O'Brien, IA

Built 1976 Load: 25.1 t ADT: 1,320

238TH STREET

Fair

Over: STREAM

075430104, Pottawattamie, IA

Built 2000 Load: 25.1 t ADT: 40

FM

Fair

Over: NORTH ENGLISH RIVER

079151602, Poweshiek, IA

Built 1957 Load: 25.1 t ADT: 40

AHRENS ST

Fair

Over: RACCOON RIVER

088362500, Sac, IA

Built 1982 Load: 25.1 t ADT: 354

IA 44

Fair

Over: MOSQUITO CREEK

0.3 mi. E of jct. IA 191, Shelby, IA

Built 1959 Load: 25.1 t ADT: 1,110

LOCAL

Fair

Over: WEST BRANCH

094452901, Sioux, IA

Built 1984 Load: 25.1 t ADT: 30

335TH LN

Fair

Over: SMALL STREAM

082223505, Story, IA

Built 1953 Load: 25.1 t ADT: 11

680TH AVE

Fair

Over: DYE CREEK

083211802, Story, IA

Built 1967 Load: 25.1 t ADT: 319

220TH ST

Fair

Over: WALNUT CREEK

083243301, Story, IA

Built 1951 Load: 25.1 t ADT: 45

LOCAL

Fair

Over: FOUR MILE CREEK

086153002, Tama, IA

Built 1988 Load: 25.1 t ADT: 11

FM

Fair

Over: CROOKED CREEK

074073003, Washington, IA

Built 1987 Load: 25.1 t ADT: 270

FM

Fair

Over: GOOSE CREEK

076062402, Washington, IA

Built 1966 Load: 25.1 t ADT: 26

FM

Fair

Over: DRAINAGE DITCH 69

089303402, Webster, IA

Built 1973 Load: 25.1 t ADT: 578

LOCAL

Fair

Over: STREAM

070163104, Appanoose, IA

Built 1979 Load: 25.2 t ADT: 16

FM

Fair

Over: PRAIRIE CREEK

083111601, Benton, IA

Built 1966 Load: 25.2 t ADT: 1,090

240TH ST

Fair

Over: CRANE CREEK

091121601, Bremer, IA

Built 1995 Load: 25.2 t ADT: 26

250TH ST

Fair

Over: CRANE CREEK

091122101, Bremer, IA

Built 1994 Load: 25.2 t ADT: 49

130TH ST

Fair

Over: DRY RUN CREEK

093142201, Bremer, IA

Built 1996 Load: 25.2 t ADT: 33

DAKOTA AVE

Fair

Over: DRY RUN CREEK

093142702, Bremer, IA

Built 1992 Load: 25.2 t ADT: 88

FM 300TH ST

Fair

Over: DRAINAGE DITCH

097352201, Clay, IA

Built 1963 Load: 25.2 t ADT: 469

IA 187

Fair

Over: BRUSH CREEK

0.5 mi. W of Jct. SR W51, Fayette, IA

Built 1936 Load: 25.2 t ADT: 700

LOCAL

Fair

Over: BLACK HAWK CREEK

088160802, Grundy, IA

Built 1983 Load: 25.2 t ADT: 20

LOCAL

Fair

Over: LITTLE SUGAR CREEK

068062604, Lee, IA

Built 1974 Load: 25.2 t ADT: 440

LOCAL

Fair

Over: HOWERDON CREEK

076292701, Madison, IA

Built 1992 Load: 25.2 t ADT: 20

LOCAL

Fair

Over: MUCHAKINOCK CREEK

075163405, Mahaska, IA

Built 1952 Load: 25.2 t ADT: 80

LOCAL

Fair

Over: DRAINAGE

076172804, Mahaska, IA

Built 1949 Load: 25.2 t ADT: 26

JERSEY AVE

Fair

Over: SUGAR CREEK

098171002, Mitchell, IA

Built 1975 Load: 25.2 t ADT: 49

Showing 4,201-4,250 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.