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

NIAGARA DR

Fair

Over: CASTLE HILL CREEK

CITY CULVERT NO. 47C, Black Hawk, IA

Built 1986 Load: 27.3 t ADT: 684

N.HACKETT RD

Fair

Over: CASTLE HILL CREEK

CITY CULVERT NO. 48C, Black Hawk, IA

Built 1986 Load: 27.3 t ADT: 395

FM

Fair

Over: BIG CREEK

082252103, Boone, IA

Built 1965 Load: 27.3 t ADT: 71

FM

Fair

Over: DES MOINES RIVER

084271307, Boone, IA

Built 1980 Load: 27.3 t ADT: 1,028

FM

Fair

Over: WAPSIPINICON RIVER

089100907, Buchanan, IA

Built 1968 Load: 27.3 t ADT: 687

FM 150TH ST

Fair

Over: BUFFALO CREEK

090073101, Buchanan, IA

Built 1985 Load: 27.3 t ADT: 98

LOCAL

Fair

Over: CREEK

090360201, Buena Vista, IA

Built 1973 Load: 27.3 t ADT: 20

GREAT RIVER RD

Fair

Over: LITTLE TURKEY RIVER

091021501, Clayton, IA

Built 1983 Load: 27.3 t ADT: 403

EAGLE RD.

Fair

Over: FITZGERALD CR

095072104, Fayette, IA

Built 1922 Load: 27.3 t ADT: 59

370 AVENUE

Fair

Over: WALNUT CREEK

069400802, Fremont, IA

Built 1969 Load: 27.3 t ADT: 229

FM

Fair

Over: SOUTH FORK BEAVER CREEK

089183606, Grundy, IA

Built 1980 Load: 27.3 t ADT: 953

LOCAL

Fair

Over: SOUTH FORK IOWA RIVER

087202604, Hardin, IA

Built 1986 Load: 27.3 t ADT: 21

260TH ST

Fair

Over: WILLOW CREEK

079433007, Harrison, IA

Built 1966 Load: 27.3 t ADT: 417

LOCAL

Fair

Over: SILVER CREEK

088391601, Ida, IA

Built 1999 Load: 27.3 t ADT: 15

LOCAL

Fair

Over: BIG BEAR CREEK

084E12701, Jackson, IA

Built 1983 Load: 27.3 t ADT: 137

A18 (140TH ST)

Fair

Over: BIG SIOUX RIVER

100493503, Lyon, IA

Built 1963 Load: 27.3 t ADT: 1,607

FM

Fair

Over: CEDAR CREEK

075173104, Mahaska, IA

Built 1971 Load: 27.3 t ADT: 150

FM

Fair

Over: BURNETT CREEK

084182305, Marshall, IA

Built 1985 Load: 27.3 t ADT: 1,061

FA-310TH ST

Fair

Over: SILVER CREEK

071410506, Mills, IA

Built 1962 Load: 27.3 t ADT: 428

MCKINLEY AVE

Fair

Over: STREAM

098420702, Osceola, IA

Built 2011 Load: 27.3 t ADT: 41

LOCAL ROAD

Fair

Over: CREEK

081222001, Polk, IA

Built 1963 Load: 27.3 t ADT: 11

LOCAL

Fair

Over: FOUR MILE CREEK

081241502, Polk, IA

Built 1970 Load: 27.3 t ADT: 50

US 59

Fair

Over: STREAM

0.6 MI. N OF S JCT SR G30, Pottawattamie, IA

Built 1952 Load: 27.3 t ADT: 1,980

FM-LOMBARDY RD

Fair

Over: SILVER CREEK

076403001, Pottawattamie, IA

Built 1981 Load: 27.3 t ADT: 50

LOCAL

Fair

Over: STREAM

070301402, Ringgold, IA

Built 1946 Load: 27.3 t ADT: 20

LOCAL

Fair

Over: STREAM

086382001, Sac, IA

Built 1973 Load: 27.3 t ADT: 11

57TH AVE

Fair

Over: WAPSIPINICON RIVER

080E20602, Scott, IA

Built 1982 Load: 27.3 t ADT: 70

FM RD F32

Fair

Over: PIGEON CREEK

802940, Shelby, IA

Built 1982 Load: 27.3 t ADT: 518

LOCAL

Fair

Over: CREEK

099080204, Winneshiek, IA

Built 1980 Load: 27.3 t ADT: 49

LOCAL

Fair

Over: COLD WATER CREEK

100093203, Winneshiek, IA

Built 1962 Load: 27.3 t ADT: 70

LOCAL

Fair

Over: WOLF CREEK

087451201, Woodbury, IA

Built 1980 Load: 27.3 t ADT: 34

FM MARQUIS RD

Fair

Over: STREAM

090130201, Black Hawk, IA

Built 2009 Load: 27.4 t ADT: 49

REMINGTION RD

Fair

Over: DRAINAGE

CITY CULVERT NO. 59C, Black Hawk, IA

Built 1989 Load: 27.4 t ADT: 617

LOCAL- M AVE

Fair

Over: CREEK

090401802, Cherokee, IA

Built 1900 Load: 27.4 t ADT: 45

EB US 20

Fair

Over: BOONE RIVER

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

Built 1974 Load: 27.4 t ADT: 5,050

LOCAL

Fair

Over: DD

092282902, Humboldt, IA

Built 1955 Load: 27.4 t ADT: 11

IA 220

Fair

Over: IOWA RIVER

1.0 MILES NORTH JCT. US 6, Iowa, IA

Built 1978 Load: 27.4 t ADT: 1,050

LOCAL

Fair

Over: BEAR CREEK

080182503, Jasper, IA

Built 1940 Load: 27.4 t ADT: 91

LOCAL ROAD

Fair

Over: WEST RAT CREEK

098432201, Lyon, IA

Built 1993 Load: 27.4 t ADT: 11

VILLAGE CREEK DR

Fair

Over: BRANCH VILLAGE CREEK

098041609, Allamakee, IA

Built 1959 Load: 27.5 t ADT: 25

LOCAL

Fair

Over: SILVER CREEK

099052905, Allamakee, IA

Built 1960 Load: 27.5 t ADT: 15

LOCAL

Fair

Over: BR UPPER IOWA RIVER

099061704, Allamakee, IA

Built 1956 Load: 27.5 t ADT: 45

330TH

Fair

Over: WHARAM CREEK

097211103, Cerro Gordo, IA

Built 1983 Load: 27.5 t ADT: 432

WAYMAN RD

Fair

Over: WAYMAN CREEK

091030705, Clayton, IA

Built 1952 Load: 27.5 t ADT: 29

FM BUCK CK RD

Fair

Over: STREAM

093033605, Clayton, IA

Built 1954 Load: 27.5 t ADT: 79

LOCAL

Fair

Over: CREEK

090E13606, Dubuque, IA

Built 1900 Load: 27.5 t ADT: 5

LOCAL

Fair

Over: DRAINAGE DITCH

089261306, Hamilton, IA

Built 1929 Load: 27.5 t ADT: 11

1380 300TH ST

Fair

Over: DD 1&2

097243001, Hancock, IA

Built 1956 Load: 27.5 t ADT: 11

FM

Fair

Over: GRITTER CREEK

078112608, Iowa, IA

Built 1969 Load: 27.5 t ADT: 470

EBYS MILL RD

Fair

Over: FARM CREEK

086011804, Jones, IA

Built 1951 Load: 27.5 t ADT: 187

Showing 4,851-4,900 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.