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: ROGG CR

097461401, Sioux, IA

Built 1969 Load: 31.4 t ADT: 71

LOCAL

Fair

Over: SMALL STREAM

097461401, Sioux, IA

Built 1973 Load: 31.4 t ADT: 71

LOCAL

Fair

Over: DAVIS CREEK

076071501, Washington, IA

Built 1963 Load: 31.4 t ADT: 15

CO RD 105

Fair

Over: DRAINAGE DITCH

100193103, Worth, IA

Built 1956 Load: 31.4 t ADT: 894

LOCAL

Fair

Over: WILDCAT CK

083100502, Benton, IA

Built 1957 Load: 31.5 t ADT: 20

LOCAL

Fair

Over: STREAM

083100502, Benton, IA

Built 1957 Load: 31.5 t ADT: 20

LOCAL

Fair

Over: BR STEIN CK

084122602, Benton, IA

Built 1958 Load: 31.5 t ADT: 20

IA 281

Fair

Over: WAPSIE RIVER OVERFLOW

2.7 MI. W OF SR V62, Black Hawk, IA

Built 1967 Load: 31.5 t ADT: 1,240

LOCAL

Fair

Over: PURGATORY CREEK

086322001, Calhoun, IA

Built 1985 Load: 31.5 t ADT: 11

FM

Fair

Over: RACCOON RIVER

086340602, Calhoun, IA

Built 1969 Load: 31.5 t ADT: 529

LOCAL

Fair

Over: DD #1 & 54

089333202, Calhoun, IA

Built 1987 Load: 31.5 t ADT: 20

150TH

Fair

Over: CREEK

094221001, Cerro Gordo, IA

Built 1950 Load: 31.5 t ADT: 39

EAGLE

Fair

Over: DRAINAGE DITCH #70

094221102, Cerro Gordo, IA

Built 1983 Load: 31.5 t ADT: 25

190TH

Fair

Over: BEAVER CREEK

095192001, Cerro Gordo, IA

Built 1961 Load: 31.5 t ADT: 304

WHEELERWOOD

Fair

Over: WINNEBAGO RIVER

097211501, Cerro Gordo, IA

Built 1933 Load: 31.5 t ADT: 69

US 59

Fair

Over: MILL CREEK

0.9 mi. N of jct. IA 3, Cherokee, IA

Built 1985 Load: 31.5 t ADT: 2,000

LOCAL

Fair

Over: SHANE CREEK

067271701, Decatur, IA

Built 1978 Load: 31.5 t ADT: 30

LOCAL

Fair

Over: SMALL STREAM

087023004, Dubuque, IA

Built 1986 Load: 31.5 t ADT: 50

IA 3 & 150

Fair

Over: OTTER CREEK

0.1 mi. N of S Jct IA 150, Fayette, IA

Built 1986 Load: 31.5 t ADT: 3,930

330 TH / E63

Fair

Over: GREENBRIAR CREEK

082303201, Greene, IA

Built 1977 Load: 31.5 t ADT: 190

S AVE / P33

Fair

Over: BUTTRICKS CREEK

084293004, Greene, IA

Built 1971 Load: 31.5 t ADT: 399

195 TH

Fair

Over: WEST BUTTRICKS CREEK

084302403, Greene, IA

Built 1970 Load: 31.5 t ADT: 180

KLINE RD

Fair

Over: BR CRANE CREEK

098132504, Howard, IA

Built 1990 Load: 31.5 t ADT: 21

US 59

Fair

Over: SILVER CREEK

1.1 mi N of N jct SR D15, Ida, IA

Built 1972 Load: 31.5 t ADT: 2,200

LOC 230TH AVE

Fair

Over: LINDNER CREEK

097273502, Kossuth, IA

Built 1986 Load: 31.5 t ADT: 11

EB US 34

Fair

Over: PONY CREEK

1.4 MI. E OF E JCT. I-29, Mills, IA

Built 1973 Load: 31.5 t ADT: 5,850

WB US 34

Fair

Over: PONY CREEK

1.4 MI. E OF E JCT. 29, Mills, IA

Built 1973 Load: 31.5 t ADT: 5,850

IA 4

Fair

Over: PILOT CREEK

1.4 mi N of SR C26, Pocahontas, IA

Built 1976 Load: 31.5 t ADT: 2,050

US 59

Fair

Over: LYON CREEK

2.6 mi. S of Jct. IA 37, Shelby, IA

Built 1970 Load: 31.5 t ADT: 3,180

IA 210

Fair

Over: CALAMUS CREEK

0.9 MILE W OF JCT SR S27, Story, IA

Built 1954 Load: 31.5 t ADT: 1,920

IA 141

Fair

Over: SMOKEY HOLLOW CREEK

0.2 mi. E of Jct. IA 31, Woodbury, IA

Built 1959 Load: 31.5 t ADT: 1,640

WHEELERWOOD

Fair

Over: STREAM

098212004, Worth, IA

Built 1960 Load: 31.5 t ADT: 265

490TH

Fair

Over: DEER CREEK

100192001, Worth, IA

Built 1971 Load: 31.5 t ADT: 47

KING BIRD

Fair

Over: GOOSE CREEK

100211404, Worth, IA

Built 1916 Load: 31.5 t ADT: 10

FM

Fair

Over: WAPSINONOC CREEK

079042002, Cedar, IA

Built 1956 Load: 31.6 t ADT: 2,480

MORMON TRK BLVD

Fair

Over: WILLOW CREEK

079061700, Johnson, IA

Built 1971 Load: 31.6 t ADT: 12,954

FM

Fair

Over: EMERY CREEK

099441502, Lyon, IA

Built 1970 Load: 31.6 t ADT: 45

SB US 75

Fair

Over: STREAM

1.3 mi. N of S.R. C-60, Plymouth, IA

Built 1948 Load: 31.6 t ADT: 7,000

LOCAL

Fair

Over: STREAM

078151601, Poweshiek, IA

Built 1959 Load: 31.6 t ADT: 26

FM

Fair

Over: CREEK

097101103, Winneshiek, IA

Built 1969 Load: 31.6 t ADT: 90

FM

Fair

Over: STREAM

074332202, Adair, IA

Built 1950 Load: 31.7 t ADT: 60

FM

Fair

Over: STREAM

075303104, Adair, IA

Built 1989 Load: 31.7 t ADT: 1,374

FM

Fair

Over: DRAINAGE DITCH

081363604, Audubon, IA

Built 1969 Load: 31.7 t ADT: 34

N UNION RD

Fair

Over: BEAVER CREEK

90-14-28-06-20, Black Hawk, IA

Built 1954 Load: 31.7 t ADT: 1,394

260TH ST

Fair

Over: CREEK

091122501, Bremer, IA

Built 1934 Load: 31.7 t ADT: 432

E53 270TH ST

Fair

Over: BRUSHY FORK CREEK

083353401, Carroll, IA

Built 1963 Load: 31.7 t ADT: 71

LOCAL

Fair

Over: SMALL STREAM

095123202, Chickasaw, IA

Built 1982 Load: 31.7 t ADT: 15

250TH AVE

Fair

Over: BLACK CREEK

082E32702, Clinton, IA

Built 1985 Load: 31.7 t ADT: 11

EB I-80

Fair

Over: NORTH RACCOON RIVER

2.3 MI. E. OF JCT. US 169, Dallas, IA

Built 1966 Load: 31.7 t ADT: 18,750

WB I-80

Fair

Over: NORTH RACCOON RIVER

2.3 MI. E OF JCT. 169, Dallas, IA

Built 1966 Load: 31.7 t ADT: 18,750

Showing 6,051-6,100 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.