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

SW 540TH ST

Fair

Over: STREAM

078072501, Johnson, IA

Built 1972 Load: 36.0 t ADT: 45

SW 520TH ST

Fair

Over: BR DEER CREEK

078082101, Johnson, IA

Built 1991 Load: 36.0 t ADT: 5

FM SAND RD

Fair

Over: STREAM

079063502, Johnson, IA

Built 1976 Load: 36.0 t ADT: 3,330

FM IVY AVE

Fair

Over: DEER CREEK

079070402, Johnson, IA

Built 1994 Load: 36.0 t ADT: 790

FM ROHRET RD

Fair

Over: DRAINAGE

079072303, Johnson, IA

Built 1900 Load: 36.0 t ADT: 270

FM SW BLK HWK D

Fair

Over: N BR OLD MAN'S CR

079080508, Johnson, IA

Built 2000 Load: 36.0 t ADT: 1,450

SW EAGLE AVE

Fair

Over: STREAM

079081504, Johnson, IA

Built 1900 Load: 36.0 t ADT: 35

280TH ST NE

Fair

Over: NICHOLSON CREEK

080052401, Johnson, IA

Built 1982 Load: 36.0 t ADT: 122

FM SO FRONT ST

Fair

Over: MUDDY CREEK

000000000, Johnson, IA

Built 2002 Load: 36.0 t ADT: 7,700

FM PRARE DU CHN

Fair

Over: BR RAPID CREEK

080062604, Johnson, IA

Built 1993 Load: 36.0 t ADT: 980

NEWPORT RD

Fair

Over: BR TURKEY CR

080062608, Johnson, IA

Built 1976 Load: 36.0 t ADT: 760

FM 250TH ST

Fair

Over: BR BUFFALO CK

080070903, Johnson, IA

Built 1978 Load: 36.0 t ADT: 920

FM JAMES AVE

Fair

Over: BUFFALO CREEK

000000000, Johnson, IA

Built 1960 Load: 36.0 t ADT: 1,990

FM 250TH ST

Fair

Over: DRAINAGE DITCH

080080903, Johnson, IA

Built 1978 Load: 36.0 t ADT: 620

SUTLIFF RD

Fair

Over: STREAM

081051903, Johnson, IA

Built 1900 Load: 36.0 t ADT: 340

SEVEN SIS RD

Fair

Over: LINGLE CREEK

081060305, Johnson, IA

Built 1979 Load: 36.0 t ADT: 35

NE HICKORY H RD

Fair

Over: W HOOSIER CR

081071303, Johnson, IA

Built 1977 Load: 36.0 t ADT: 300

LINN-JOHNSON RD

Fair

Over: STREAM

081080501, Johnson, IA

Built 1974 Load: 36.0 t ADT: 60

FM 120TH ST

Fair

Over: BR PLUM CR

081081201, Johnson, IA

Built 1989 Load: 36.0 t ADT: 1,630

LOCAL

Fair

Over: HOCKEYS SLOUGH

077051202, Johnson, IA

Built 2001 Load: 36.0 t ADT: 40

COUNTY RD. X-28

Fair

Over: WAPSIPINICON RIVER

084040607, Jones, IA

Built 1971 Load: 36.0 t ADT: 550

SUTLIFF RD

Fair

Over: SPRING CREEK

082052404, Linn, IA

Built 1962 Load: 36.0 t ADT: 610

SAWYER RD

Fair

Over: SAWYER CREEK

085060105, Linn, IA

Built 1925 Load: 36.0 t ADT: 1,100

MONTICELLO RD

Fair

Over: TRIB BOULDER CR

086050901, Linn, IA

Built 1960 Load: 36.0 t ADT: 530

TROY MILLS RD

Fair

Over: TRIB.TO WAPSIPINICON R

086071704, Linn, IA

Built 1925 Load: 36.0 t ADT: 1,424

KIRKWOOD AVE

Fair

Over: SUGAR CREEK

098171104, Mitchell, IA

Built 1974 Load: 36.0 t ADT: 70

IA 31

Fair

Over: LITTLE SIOUX RIVER

0.8 mi S of jct US 20, Woodbury, IA

Built 1973 Load: 36.0 t ADT: 1,120

FM

Fair

Over: PRAIRIE CREEK D D #1

090352602, Buena Vista, IA

Built 1978 Load: 36.1 t ADT: 90

FM

Fair

Over: DD 34 LAT #2

093353502, Buena Vista, IA

Built 1979 Load: 36.1 t ADT: 489

IA 57

Fair

Over: DRAINAGE DITCH

4.8 mi. E of Jct. IA 14, Butler, IA

Built 1971 Load: 36.1 t ADT: 2,220

LOCAL

Fair

Over: D D #7

099322101, Emmet, IA

Built 1977 Load: 36.1 t ADT: 15

LOCAL

Fair

Over: CREEK

095151403, Floyd, IA

Built 1990 Load: 36.1 t ADT: 29

FM

Fair

Over: BRANCH BEAVER CREEK

089172301, Grundy, IA

Built 1970 Load: 36.1 t ADT: 501

LINN-JOHNSON RD

Fair

Over: STREAM

081080401, Johnson, IA

Built 1975 Load: 36.1 t ADT: 102

IA 92

Fair

Over: GERMAN CREEK

3.0 MI. E OF E JCT. IA149, Keokuk, IA

Built 1967 Load: 36.1 t ADT: 1,880

FM

Fair

Over: WHIPPOORWILL CK

073181701, Monroe, IA

Built 1951 Load: 36.1 t ADT: 230

US 71 & IA 2

Fair

Over: WEST NODAWAY RIVER

0.3 MI. S OF N JCT. 2, Page, IA

Built 1972 Load: 36.1 t ADT: 3,360

IA 1

Fair

Over: WALNUT CREEK

4.0 mi. N of Jct IA 78, Washington, IA

Built 2006 Load: 36.1 t ADT: 2,340

FM

Fair

Over: WEST FORK NODAWAY RIVER

074332105, Adair, IA

Built 1979 Load: 36.2 t ADT: 249

FM

Fair

Over: NORTH RACCOON RIVER

081280801, Dallas, IA

Built 1980 Load: 36.2 t ADT: 139

LOCAL ROAD

Fair

Over: WOLF X CREEK

087182501, Grundy, IA

Built 1957 Load: 36.2 t ADT: 11

FM SW 540TH AVE

Fair

Over: DEER CREEK

078082903, Johnson, IA

Built 1976 Load: 36.2 t ADT: 900

NB IA 13

Fair

Over: EAST INDIAN CREEK

2.1 mi. N of Jct. SR E34, Linn, IA

Built 1973 Load: 36.2 t ADT: 3,600

WEST T AVE

Fair

Over: WEST BR INDIAN CREEK

083230103, Story, IA

Built 1997 Load: 36.2 t ADT: 139

260 TH STREET

Fair

Over: EAST NODAWAY RIVER

071352901, Adams, IA

Built 1976 Load: 36.3 t ADT: 439

S ELK RUN RD

Fair

Over: ELK RUN CREEK

89-12-34-04, Black Hawk, IA

Built 1971 Load: 36.3 t ADT: 3,574

LOCAL

Fair

Over: BEAVER CREEK

082280903, Boone, IA

Built 1975 Load: 36.3 t ADT: 40

FM

Fair

Over: BIG CREEK

083253301, Boone, IA

Built 1992 Load: 36.3 t ADT: 977

FM 252ND ST

Fair

Over: BUCK CREEK

091112203, Bremer, IA

Built 1972 Load: 36.3 t ADT: 334

FM - YANKTON

Fair

Over: CLARKS BRANCH

074373203, Cass, IA

Built 1990 Load: 36.3 t ADT: 60

Showing 7,701-7,750 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.