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 ST

Fair

Over: SMALL

080021201, Cedar, IA

Built 2005 Load: 23.4 t ADT: 60

LOCAL

Fair

Over: CREEK

093291303, Humboldt, IA

Built 1954 Load: 23.4 t ADT: 40

LOCAL

Fair

Over: STREAM

074100403, Keokuk, IA

Built 1994 Load: 23.4 t ADT: 15

LOCAL

Fair

Over: STREAM

074112102, Keokuk, IA

Built 1971 Load: 23.4 t ADT: 30

FM

Fair

Over: ARGO SLOUGH

099431202, Lyon, IA

Built 1977 Load: 23.4 t ADT: 789

LOCAL

Fair

Over: ENGLISH CREEK

075191006, Marion, IA

Built 1953 Load: 23.4 t ADT: 187

LOCAL

Fair

Over: STREAM

099390902, Osceola, IA

Built 1944 Load: 23.4 t ADT: 26

NB I-35,EB I-80

Fair

Over: SAYLOR CREEK

0.5 MI. W OF JCT. 415, Polk, IA

Built 1958 Load: 23.4 t ADT: 43,750

LOCAL ROAD

Fair

Over: CREEK

098102802, Winneshiek, IA

Built 1900 Load: 23.4 t ADT: 59

LOCAL

Fair

Over: CREEK

099072305, Winneshiek, IA

Built 1900 Load: 23.4 t ADT: 70

LOCAL

Fair

Over: FARMERS DITCH

086462401, Woodbury, IA

Built 1980 Load: 23.4 t ADT: 20

LOCAL

Fair

Over: MOREHEAD CREEK

087422501, Woodbury, IA

Built 1987 Load: 23.4 t ADT: 26

FM

Fair

Over: DD 13

088322201, Calhoun, IA

Built 1972 Load: 23.5 t ADT: 26

320TH ST

Fair

Over: FIELD STREAM

082333001, Carroll, IA

Built 1900 Load: 23.5 t ADT: 29

FM

Fair

Over: FIELD STREAM

083360102, Carroll, IA

Built 1986 Load: 23.5 t ADT: 34

LOCAL - 760TH

Fair

Over: STALE BRANCH

074342302, Cass, IA

Built 1986 Load: 23.5 t ADT: 11

205TH ST

Fair

Over: ROCK CREEK

081032603, Cedar, IA

Built 1996 Load: 23.5 t ADT: 40

IA 2

Fair

Over: WEST NISHNABOTNA RIVER

1.7 MI. E OF E JCT US 275, Fremont, IA

Built 1954 Load: 23.5 t ADT: 2,050

190 TH / E33

Fair

Over: HARDIN CREEK

084312301, Greene, IA

Built 1961 Load: 23.5 t ADT: 270

FM

Fair

Over: DRAINAGE

074270708, Madison, IA

Built 1978 Load: 23.5 t ADT: 60

SB US 75

Fair

Over: DRAINAGE DITCH

2.6 mi S of jct SR C44, Plymouth, IA

Built 1948 Load: 23.5 t ADT: 7,000

FM

Fair

Over: FOUR MILE CREEK

080233205, Polk, IA

Built 1966 Load: 23.5 t ADT: 5,776

LOCAL

Fair

Over: ROCK CREEK

080131002, Poweshiek, IA

Built 1955 Load: 23.5 t ADT: 5

200TH ST

Fair

Over: DYE CREEK

084212901, Story, IA

Built 1950 Load: 23.5 t ADT: 40

SWAN RD

Fair

Over: CREEK

097103403, Winneshiek, IA

Built 1900 Load: 23.5 t ADT: 33

LOCAL

Fair

Over: CREEK

099101006, Winneshiek, IA

Built 1900 Load: 23.5 t

LOCAL

Fair

Over: WILLOW CREEK

083330301, Carroll, IA

Built 1900 Load: 23.6 t ADT: 26

LOCAL

Fair

Over: FIELD STREAM

085363201, Carroll, IA

Built 1990 Load: 23.6 t ADT: 40

HARDING AVE

Fair

Over: SMALL

079033202, Cedar, IA

Built 1997 Load: 23.6 t ADT: 15

230TH ST

Fair

Over: STREAM

080010901, Cedar, IA

Built 1999 Load: 23.6 t ADT: 71

PARKSIDE DRIVE

Fair

Over: WAPSINONOC CREEK

0.4 MILES NORTH OF INTERS, Cedar, IA

Built 1970 Load: 23.6 t ADT: 400

SECOND STREET

Fair

Over: WAPSINONOC CREEK

0.1 MILES EAST OF PARKSID, Cedar, IA

Built 1976 Load: 23.6 t ADT: 230

185 TH/FARM DR

Fair

Over: DD #110

084301703, Greene, IA

Built 1925 Load: 23.6 t ADT: 11

LOCAL

Fair

Over: TETE DE MORTS CREEK

087E41802, Jackson, IA

Built 1982 Load: 23.6 t ADT: 50

LOCAL

Fair

Over: DRAINAGE

077282702, Madison, IA

Built 1949 Load: 23.6 t ADT: 50

NOBLE AVE

Fair

Over: CREEK

097160504, Mitchell, IA

Built 1974 Load: 23.6 t ADT: 29

I 880 EB

Fair

Over: BNSF RR

0.3 MI. E OF JCT. 191, Pottawattamie, IA

Built 1966 Load: 23.6 t ADT: 2,850

IDELWOOD ROAD

Fair

Over: STREAM

075390103, Pottawattamie, IA

Built 1998 Load: 23.6 t ADT: 20

LOCAL

Fair

Over: GOOSEBURY CREEK

069292301, Ringgold, IA

Built 1956 Load: 23.6 t ADT: 15

FM

Fair

Over: KIBBE CREEK

084141102, Tama, IA

Built 1991 Load: 23.6 t ADT: 29

LOCAL

Fair

Over: BR YELLOW RIVER

096051306, Allamakee, IA

Built 1975 Load: 23.7 t ADT: 88

LOCAL

Fair

Over: LEWIS JONES CREEK

098051504, Allamakee, IA

Built 1975 Load: 23.7 t ADT: 88

FM

Fair

Over: BEAR CREEK

100063006, Allamakee, IA

Built 1954 Load: 23.7 t ADT: 69

E BIG ROCK RD

Fair

Over: VIRDEN CREEK

89-12-06-01-10, Black Hawk, IA

Built 1949 Load: 23.7 t ADT: 29

E DONALD ST

Fair

Over: TRIB TO ELK RUN CREEK

89-12-14-03-10, Black Hawk, IA

Built 1971 Load: 23.7 t ADT: 1,375

POSTEL AVE

Fair

Over: SMALL STREAM

8808220044, Buchanan, IA

Built 2011 Load: 23.7 t ADT: 69

600TH ST

Fair

Over: WILLOW CREEK

090410601, Cherokee, IA

Built 1937 Load: 23.7 t ADT: 11

330TH ST

Fair

Over: STONY CREEK

096370603, Clay, IA

Built 1965 Load: 23.7 t ADT: 41

165TH ST

Fair

Over: STREAM

094040603, Clayton, IA

Built 1975 Load: 23.7 t ADT: 47

KANE RD

Fair

Over: CREEK

088E31903, Dubuque, IA

Built 2000 Load: 23.7 t ADT: 240

Showing 3,701-3,750 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.