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

Fair

Over: NICHOLSON CREEK

080042001, Cedar, IA

Built 1975 Load: 30.0 t ADT: 210

LOCAL

Fair

Over: SIMPSON CREEK

095112602, Chickasaw, IA

Built 1981 Load: 30.0 t ADT: 21

410TH AVE.

Fair

Over: SOUTH BRANCH ELK RIVER

083E62902, Clinton, IA

Built 1989 Load: 30.0 t ADT: 62

LOCAL

Fair

Over: MIDDLE FORK MAQUOKETA

089010303, Dubuque, IA

Built 1972 Load: 30.0 t ADT: 290

100TH ST

Fair

Over: STOE CREEK

092102003, Fayette, IA

Built 1971 Load: 30.0 t ADT: 344

FM

Fair

Over: DRY RUN CREEK

094152003, Floyd, IA

Built 1979 Load: 30.0 t ADT: 530

FM SPRUCE AVE

Fair

Over: N BEAVER CREEK

090193102, Franklin, IA

Built 1971 Load: 30.0 t ADT: 177

FM

Fair

Over: OLD MANS CREEK

079092701, Iowa, IA

Built 1976 Load: 30.0 t ADT: 20

FM

Fair

Over: DRAINAGE

081120203, Iowa, IA

Built 1976 Load: 30.0 t ADT: 30

FM

Fair

Over: SUGAR CREEK

080171403, Jasper, IA

Built 1978 Load: 30.0 t ADT: 150

LOCAL

Fair

Over: ELK CREEK

080193609, Jasper, IA

Built 2000 Load: 30.0 t ADT: 155

FM 180TH ST

Fair

Over: STREAM

081052303, Johnson, IA

Built 1978 Load: 30.0 t ADT: 180

FM 220TH AVE

Fair

Over: BUFFALO CREEK

097271002, Kossuth, IA

Built 1975 Load: 30.0 t ADT: 180

FM 310TH ST

Fair

Over: BLACK CAT CREEK

097302101, Kossuth, IA

Built 1973 Load: 30.0 t ADT: 538

LOC 365TH ST

Fair

Over: MUD CREEK

098281903, Kossuth, IA

Built 1972 Load: 30.0 t ADT: 103

LOCAL

Fair

Over: CREEK

067060702, Lee, IA

Built 1975 Load: 30.0 t ADT: 34

LOCAL

Fair

Over: OTTER CREEK

073040101, Louisa, IA

Built 1972 Load: 30.0 t ADT: 35

FM

Fair

Over: TURKEY RUN

074030903, Louisa, IA

Built 1978 Load: 30.0 t ADT: 120

LOCAL ROAD

Fair

Over: GILBERTSON CREEK

099471902, Lyon, IA

Built 1975 Load: 30.0 t ADT: 81

FM

Fair

Over: THUNDER CREEK

077182804, Marion, IA

Built 1975 Load: 30.0 t ADT: 330

IA 48

Fair

Over: EAST NISHNABOTNA RIVER

1.7 MI. N OF JCT. 34, Montgomery, IA

Built 1973 Load: 30.0 t ADT: 2,080

FM K-49

Fair

Over: WHISKEY CREEK

091452702, Plymouth, IA

Built 1974 Load: 30.0 t ADT: 818

L-22

Fair

Over: LITTLE SIOUX RIVER

092432402, Plymouth, IA

Built 1974 Load: 30.0 t ADT: 139

FM C-38

Fair

Over: DRAINAGE

092453301, Plymouth, IA

Built 1977 Load: 30.0 t ADT: 1,615

LOCAL

Fair

Over: DRAINAGE DITCH NO. 22

090313002, Pocahontas, IA

Built 1977 Load: 30.0 t ADT: 20

LOCAL RD

Fair

Over: NORTH LIZARD CREEK DD#77

091310801, Pocahontas, IA

Built 1979 Load: 30.0 t ADT: 45

LOCAL RD

Fair

Over: NORTH LIZARD CREEK

092313101, Pocahontas, IA

Built 1979 Load: 30.0 t ADT: 34

FM

Fair

Over: NO LIZARD CK DD #77

092322201, Pocahontas, IA

Built 1978 Load: 30.0 t ADT: 20

LOCAL

Fair

Over: NO LIZARD CK DD #77

092322502, Pocahontas, IA

Built 1976 Load: 30.0 t ADT: 40

LOCAL

Fair

Over: BEAVER CREEK

093311901, Pocahontas, IA

Built 1977 Load: 30.0 t ADT: 15

FM

Fair

Over: BEAVER CREEK

093312002, Pocahontas, IA

Built 1977 Load: 30.0 t ADT: 230

LOCAL

Fair

Over: BEAVER CREEK

093313402, Pocahontas, IA

Built 1978 Load: 30.0 t ADT: 50

FM

Fair

Over: NORTH ENGLISH RIVER

079150802, Poweshiek, IA

Built 1972 Load: 30.0 t ADT: 90

FM

Fair

Over: E BIG CREEK

067281201, Ringgold, IA

Built 1973 Load: 30.0 t ADT: 349

LOCAL

Fair

Over: STREAM

067300804, Ringgold, IA

Built 1936 Load: 30.0 t ADT: 5

FM

Fair

Over: NO NAME CREEK

089380502, Sac, IA

Built 1971 Load: 30.0 t ADT: 450

FM

Fair

Over: HALFWAY CREEK

089382902, Sac, IA

Built 1973 Load: 30.0 t ADT: 319

FM

Fair

Over: SIXMILE CREEK

095460301, Sioux, IA

Built 1972 Load: 30.0 t ADT: 1,926

US 63

Fair

Over: DRAINAGE DITCH

3.0 MILES S OF JCT SR E29, Tama, IA

Built 1976 Load: 30.0 t ADT: 3,100

US 34 & 169

Fair

Over: GRAND RIVER

1.2 mi. W of E Jct US 169, Union, IA

Built 1971 Load: 30.0 t ADT: 3,450

IA 149 NB

Fair

Over: DME RR

3.9 mi. N of Jct. U.S. 34, Wapello, IA

Built 1963 Load: 30.0 t ADT: 3,500

LOCAL

Fair

Over: ELLIOTT CREEK

088461501, Woodbury, IA

Built 1978 Load: 30.0 t ADT: 15

LOCAL

Fair

Over: BIG WHISKEY CREEK

089462301, Woodbury, IA

Built 1978 Load: 30.0 t ADT: 30

LOCAL

Fair

Over: HICKORY CREEK

096053304, Allamakee, IA

Built 1982 Load: 30.1 t ADT: 70

LOCAL

Fair

Over: VILLAGE CREEK

098052407, Allamakee, IA

Built 1960 Load: 30.1 t ADT: 44

BEE RD

Fair

Over: WATERLOO CREEK

100060906, Allamakee, IA

Built 1960 Load: 30.1 t ADT: 26

UNIVERSITY AVE

Fair

Over: DRY RUN CREEK

000000000, Black Hawk, IA

Built 1971 Load: 30.1 t ADT: 7,792

US 169

Fair

Over: BRANCH BEAVER CREEK

1.9 MI N OF W JCT US 30, Boone, IA

Built 1967 Load: 30.1 t ADT: 1,890

FM- 610TH ST

Fair

Over: PITCHER CREEK

090390901, Cherokee, IA

Built 1970 Load: 30.1 t ADT: 1,017

LOCAL

Fair

Over: BUCK CREEK

082400105, Crawford, IA

Built 1973 Load: 30.1 t ADT: 11

Showing 5,451-5,500 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.