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

FM 90TH AVE

Poor

Over: FOUR MILE CREEK

095292802, Kossuth, IA

Built 1965 Load: 3.4 t ADT: 638

LOCAL

Poor

Over: DEEP RIVER

078130102, Poweshiek, IA

Built 1983 Load: 3.4 t ADT: 20

LOCAL

Poor

Over: BEAVER CREEK

082280304, Boone, IA

Built 1915 Load: 3.6 t ADT: 20

100TH ST

Poor

Over: KEIGLEY BRANCH

085240501, Story, IA

Built 1900 Load: 3.6 t ADT: 15

LOCAL

Poor

Over: W 102 RIVER

069351605, Taylor, IA

Built 1963 Load: 3.6 t ADT: 5

FM

Poor

Over: SOLDIER RIVER

085412002, Crawford, IA

Built 1957 Load: 3.7 t ADT: 40

FOX RD.

Poor

Over: VOLGA RIVER

093073003, Fayette, IA

Built 1905 Load: 3.7 t ADT: 15

FIELD ENTRANCE

Poor

Over: TRIB DES MOINES RIVER

084272305, Boone, IA

Built 1900 Load: 3.8 t ADT: 40

FM

Poor

Over: PAINTER CREEK

075252404, Warren, IA

Built 1900 Load: 4.0 t ADT: 71

LOCAL

Poor

Over: INDIAN CREEK

068163404, Appanoose, IA

Built 1900 Load: 4.2 t ADT: 5

LOCAL

Poor

Over: CLARKS CREEK

074373204, Cass, IA

Built 1966 Load: 4.2 t ADT: 5

LOCAL

Poor

Over: PUMPKIN CREEK

084E22003, Jackson, IA

Built 1950 Load: 4.2 t ADT: 11

FM

Poor

Over: DRAINAGE DITCH NO 69

088302301, Webster, IA

Built 1981 Load: 4.2 t ADT: 34

LOCAL

Poor

Over: WOLF CREEK

071080509, Jefferson, IA

Built 1900 Load: 4.3 t ADT: 15

BRIDGE ST

Poor

Over: TURKEY RIVER

C25050530, Clayton, IA

Built 1889 Load: 4.5 t ADT: 4,755

FM

Poor

Over: MIDDLE RIVER

079333604, Guthrie, IA

Built 1969 Load: 4.5 t ADT: 450

G13 110TH ST

Poor

Over: N SKUNK RIVER

077150703, Mahaska, IA

Built 1960 Load: 4.5 t ADT: 35

720TH AVE

Poor

Over: HARDIN-STORY DD 1

085211104, Story, IA

Built 1900 Load: 4.5 t ADT: 15

LOCAL

Poor

Over: FARMERS DITCH

088472604, Woodbury, IA

Built 2000 Load: 4.5 t ADT: 30

QUINCE AVE

Poor

Over: STREAM

071333602, Adams, IA

Built 1978 Load: 4.6 t ADT: 20

LOCAL

Poor

Over: E FORK DES MOINES RIVER

0100321105, Emmet, IA

Built 1914 Load: 4.6 t ADT: 26

265TH ST

Poor

Over: CREEK

080E23303, Scott, IA

Built 1996 Load: 4.7 t ADT: 35

FM

Poor

Over: LITTLE MAPLE RIVER

090382101, Buena Vista, IA

Built 1974 Load: 4.8 t ADT: 569

LOCAL

Poor

Over: SMALL STREAM

090161901, Butler, IA

Built 1956 Load: 4.8 t ADT: 74

LOCAL

Poor

Over: LITTLE EAGLE CREEK

092252601, Wright, IA

Built 1973 Load: 4.8 t ADT: 21

FM

Poor

Over: SMALL

082011403, Cedar, IA

Built 1980 Load: 5.3 t ADT: 110

LOCAL ROAD

Poor

Over: CREEK

098103409, Winneshiek, IA

Built 1900 Load: 5.3 t ADT: 39

LOCAL

Poor

Over: SMALL STREAM

091153203, Butler, IA

Built 1966 Load: 5.4 t ADT: 70

LOCAL

Poor

Over: W FK W NISHNABOTNA RIVER

082381401, Crawford, IA

Built 1987 Load: 5.4 t ADT: 21

FM-175TH ST

Poor

Over: CRANE CREEK

098123103, Howard, IA

Built 1955 Load: 5.4 t ADT: 59

FM

Poor

Over: UPPER IOWA RIVER

100102105, Winneshiek, IA

Built 1913 Load: 5.4 t ADT: 39

215TH ST

Poor

Over: DES MOINES RIVER

092293403, Humboldt, IA

Built 1899 Load: 5.6 t ADT: 50

LOCAL RD

Poor

Over: DRAINAGE

075292305, Madison, IA

Built 1900 Load: 5.6 t ADT: 15

LOCAL

Poor

Over: SMALL STREAM

089361003, Sac, IA

Built 1980 Load: 5.6 t ADT: 15

LOCAL

Poor

Over: SMALL RUNNING CREEK

098101003, Winneshiek, IA

Built 1900 Load: 5.7 t ADT: 29

LOCAL

Poor

Over: DRAINAGE DITCH

093381006, Buena Vista, IA

Built 1973 Load: 5.9 t ADT: 30

PIONEER AVE

Poor

Over: DEEP CREEK

092440302, Plymouth, IA

Built 1917 Load: 5.9 t ADT: 30

LOCAL

Poor

Over: CREEK

096093404, Winneshiek, IA

Built 1944 Load: 5.9 t ADT: 44

FM

Poor

Over: BRANCH LONG CREEK

071270504, Clarke, IA

Built 1952 Load: 6.0 t ADT: 15

R AVE.

Poor

Over: UNAMED CR

091091704, Fayette, IA

Built 1917 Load: 6.0 t ADT: 20

40TH ST

Poor

Over: OTTER CR

091091903, Fayette, IA

Built 1917 Load: 6.0 t ADT: 88

LOCAL

Poor

Over: S. FORK LONG CREEK

076083602, Washington, IA

Built 1953 Load: 6.0 t ADT: 71

MALLARD AVE

Poor

Over: BUFFALO CREEK

093203104, Franklin, IA

Built 1971 Load: 6.2 t ADT: 30

OLD BR.RD.

Poor

Over: PRAIRIE CREEK

082081204, Linn, IA

Built 1906 Load: 6.2 t ADT: 110

LOCAL

Poor

Over: MIDDLE RIVER

077311701, Adair, IA

Built 1958 Load: 6.3 t ADT: 41

LOCAL

Poor

Over: NISHNABOTNA RIVER

079352203, Audubon, IA

Built 1958 Load: 6.3 t ADT: 35

LOCAL

Poor

Over: TIPTON CREEK

087212502, Hardin, IA

Built 1989 Load: 6.3 t ADT: 35

LOC 110TH ST

Poor

Over: DRAINAGE DITCH 182

094283101, Kossuth, IA

Built 1951 Load: 6.3 t ADT: 41

LOCAL

Poor

Over: ENGLISH CREEK

073210101, Lucas, IA

Built 1979 Load: 6.3 t ADT: 11

FM

Poor

Over: HONEY CREEK

068331402, Taylor, IA

Built 1958 Load: 6.3 t ADT: 11

Showing 16,651-16,700 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.