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: CREEK

079E21508, Scott, IA

Built 1952 Load: 19.8 t ADT: 70

FM

Fair

Over: W NISHNABOTNA RIVER

081373103, Shelby, IA

Built 1960 Load: 19.8 t ADT: 668

FM

Fair

Over: MOSER CREEK

081392103, Shelby, IA

Built 1962 Load: 19.8 t ADT: 50

FM

Fair

Over: BRANCH TWELVE MILE CREEK

086152502, Tama, IA

Built 1965 Load: 19.8 t ADT: 44

FM

Fair

Over: PURGATORY CREEK

085331201, Carroll, IA

Built 1977 Load: 19.9 t ADT: 60

LOCAL

Fair

Over: SUGAR CREEK

081020703, Cedar, IA

Built 1986 Load: 19.9 t ADT: 50

210TH ST

Fair

Over: GOLLS CREEK

095230801, Hancock, IA

Built 2012 Load: 19.9 t ADT: 62

FM

Fair

Over: BRANDY WINE CREEK

072060901, Henry, IA

Built 1966 Load: 19.9 t ADT: 340

FM

Fair

Over: SMALL STREAM

081182202, Jasper, IA

Built 1992 Load: 19.9 t ADT: 20

29TH ST DR SE

Fair

Over: INDIAN CREEK

000000000, Linn, IA

Built 1972 Load: 19.9 t ADT: 5,800

LOCAL RD

Fair

Over: MINOR DRAINAGE

073370503, Montgomery, IA

Built 1998 Load: 19.9 t ADT: 26

EAGLE LANE

Fair

Over: LITTLE SILVER CREEK

075422404, Pottawattamie, IA

Built 1990 Load: 19.9 t ADT: 5

YORK ROAD

Fair

Over: KEG CREEK

077410201, Pottawattamie, IA

Built 1977 Load: 19.9 t ADT: 34

LOCAL ROAD

Fair

Over: BRANCH SQUAW CREEK

074243403, Warren, IA

Built 1949 Load: 19.9 t ADT: 21

FM

Fair

Over: TEN MILE CREEK

098091801, Winneshiek, IA

Built 2005 Load: 19.9 t ADT: 393

230TH STREET

Fair

Over: STREAM

071321001, Adams, IA

Built 1960 Load: 20.0 t ADT: 26

230TH STREET

Fair

Over: METZ CREEK

071321001, Adams, IA

Built 1958 Load: 20.0 t ADT: 26

FM-250TH STREET

Fair

Over: PLATTE RIVER

071322401, Adams, IA

Built 1967 Load: 20.0 t ADT: 34

REDWOOD AVENUE

Fair

Over: STREAM

071323102, Adams, IA

Built 1961 Load: 20.0 t ADT: 11

POPLAR AVENUE

Fair

Over: W BRANCH 102 RIVER

071331104, Adams, IA

Built 1956 Load: 20.0 t ADT: 11

170TH STREET

Fair

Over: STREAM

072331201, Adams, IA

Built 1964 Load: 20.0 t ADT: 20

140TH STREET

Fair

Over: STREAM

073342703, Adams, IA

Built 1961 Load: 20.0 t ADT: 15

LOCAL 240TH ST

Fair

Over: PINE CR

088081701, Buchanan, IA

Built 1961 Load: 20.0 t ADT: 16

LOCAL 265TH ST

Fair

Over: BEAR CR

088092703, Buchanan, IA

Built 1962 Load: 20.0 t ADT: 196

LOC 110TH ST

Fair

Over: HUNTER CR

090090701, Buchanan, IA

Built 1963 Load: 20.0 t ADT: 73

LOC CENTRAL AVE

Fair

Over: SMALL STREAM

090101604, Buchanan, IA

Built 1967 Load: 20.0 t ADT: 91

LOCAL

Fair

Over: SMALL STREAM

092172202, Butler, IA

Built 1952 Load: 20.0 t ADT: 36

FM

Fair

Over: BEAVER CREEK

082343602, Carroll, IA

Built 1955 Load: 20.0 t ADT: 45

LOCAL

Fair

Over: FIELD STREAM

082362103, Carroll, IA

Built 1975 Load: 20.0 t ADT: 40

LOCAL

Fair

Over: WEST NISHNABOTNA RIVER

083362701, Carroll, IA

Built 1958 Load: 20.0 t ADT: 29

FM

Fair

Over: MARROWBONE CREEK

085330701, Carroll, IA

Built 1959 Load: 20.0 t ADT: 110

LOCAL

Fair

Over: ELK RUN

085341206, Carroll, IA

Built 1958 Load: 20.0 t ADT: 50

FM

Fair

Over: BEAMAN CREEK

085360602, Carroll, IA

Built 1900 Load: 20.0 t ADT: 748

FM

Fair

Over: FIELD STREAM

085363602, Carroll, IA

Built 1959 Load: 20.0 t ADT: 34

LOCAL

Fair

Over: OTTER CR

079011901, Cedar, IA

Built 1960 Load: 20.0 t ADT: 46

FM

Fair

Over: MASONS CREEK

081041405, Cedar, IA

Built 1953 Load: 20.0 t ADT: 70

FM

Fair

Over: E FORK WAPSIPINICON

095123402, Chickasaw, IA

Built 1952 Load: 20.0 t ADT: 108

LOCAL

Fair

Over: WEST CREEK

073251502, Clarke, IA

Built 1970 Load: 20.0 t ADT: 45

FM

Fair

Over: SLOUGH

081272702, Dallas, IA

Built 1928 Load: 20.0 t ADT: 20

FM

Fair

Over: SOAP CREEK

070120504, Davis, IA

Built 1954 Load: 20.0 t ADT: 100

FM

Fair

Over: SMALL STREAM(SIDE DITCH)

070131104, Davis, IA

Built 1996 Load: 20.0 t ADT: 10

RAMP TO WB US 34

Fair

Over: PARKING LOT

0.4 mi. W of IL St. Line, Des Moines, IA

Built 1972 Load: 20.0 t ADT: 1,940

FM OLIVE AVE

Fair

Over: SMALL STREAM

091200902, Franklin, IA

Built 1953 Load: 20.0 t ADT: 59

NETTLE AVE

Fair

Over: BAILEYE CREEK

093200508, Franklin, IA

Built 1975 Load: 20.0 t ADT: 47

K AVE

Fair

Over: GREENBRIER CREEK

082310202, Greene, IA

Built 1936 Load: 20.0 t ADT: 15

FM - 335TH ST

Fair

Over: KEG CREEK

078413501, Harrison, IA

Built 1955 Load: 20.0 t ADT: 50

CRANE CREEK RD

Fair

Over: BR CRANE CREEK

098131501, Howard, IA

Built 1958 Load: 20.0 t ADT: 39

10TH ST

Fair

Over: BRANCH UPPER IOWA RIVER

100120703, Howard, IA

Built 1988 Load: 20.0 t ADT: 51

10TH ST

Fair

Over: BRANCH UPPER IOWA RIVER

100131103, Howard, IA

Built 1997 Load: 20.0 t ADT: 73

LOCAL

Fair

Over: DD

092270802, Humboldt, IA

Built 1900 Load: 20.0 t ADT: 50

Showing 2,551-2,600 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.