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: STREAM

069162604, Appanoose, IA

Built 1992 Load: 32.7 t ADT: 15

LOCAL

Fair

Over: UNNAMED STREAM

069182404, Appanoose, IA

Built 1976 Load: 32.7 t ADT: 200

LOCAL

Fair

Over: FISH BRANCH CREEK

069190805, Appanoose, IA

Built 1975 Load: 32.7 t ADT: 26

LOCAL

Fair

Over: BUZZARD CREEK

070160804, Appanoose, IA

Built 1988 Load: 32.7 t ADT: 5

LOCAL

Fair

Over: SMALL STREAM

070173010, Appanoose, IA

Built 1994 Load: 32.7 t ADT: 26

FM

Fair

Over: BLUE GRASS CREEK

080353403, Audubon, IA

Built 1993 Load: 32.7 t ADT: 120

LOCAL

Fair

Over: BR MUD CREEK

082090601, Benton, IA

Built 1972 Load: 32.7 t ADT: 15

LOCAL (LWC)

Fair

Over: MUD CREEK

083102101, Benton, IA

Built 1988 Load: 32.7 t ADT: 79

LOCAL

Fair

Over: POSSUM CREEK

084101002, Benton, IA

Built 1985 Load: 32.7 t ADT: 39

LOCAL

Fair

Over: POSSUM CREEK

084101102, Benton, IA

Built 1985 Load: 32.7 t ADT: 33

FM

Fair

Over: HINKLE CREEK

085113303, Benton, IA

Built 1991 Load: 32.7 t ADT: 900

LOCAL

Fair

Over: SPRING CREEK

086110305, Benton, IA

Built 1997 Load: 32.7 t ADT: 11

LOCAL

Fair

Over: BR PRAIRIE CREEK

083113001, Benton, IA

Built 1988 Load: 32.7 t ADT: 45

LOCAL

Fair

Over: STERN CREEK

082120401, Benton, IA

Built 1989 Load: 32.7 t ADT: 30

FM

Fair

Over: SMALL STREAM

086112502, Benton, IA

Built 1991 Load: 32.7 t ADT: 540

LOCAL

Fair

Over: BUFFALO CREEK

082100801, Benton, IA

Built 1996 Load: 32.7 t ADT: 24

69TH ST

Fair

Over: SMALL STREAM

083111001, Benton, IA

Built 1996 Load: 32.7 t ADT: 30

13TH STREET

Fair

Over: MINNOW CREEK

082122000, Benton, IA

Built 2001 Load: 32.7 t ADT: 2,103

US 218

Fair

Over: STREAM

4.3 mi. S of Jct. U.S. 20, Black Hawk, IA

Built 1952 Load: 32.7 t ADT: 4,110

VINCENT RD

Fair

Over: CASTLE HILL CREEK

CITY CULVERT NO. 46C, Black Hawk, IA

Built 1988 Load: 32.7 t ADT: 684

SARAH DRIVE

Fair

Over: DRAINAGE

CITY CULVERT NO. 55C, Black Hawk, IA

Built 1993 Load: 32.7 t ADT: 2,967

US 20

Fair

Over: DRAINAGE DITCH

1.3 mi. W of jct. SR V65, Black Hawk, IA

Built 1980 Load: 32.7 t ADT: 10,700

260TH ST

Fair

Over: BUCK CREEK

091112601, Bremer, IA

Built 1977 Load: 32.7 t ADT: 29

JOPLIN RD

Fair

Over: SMALL STREAM

091132202, Bremer, IA

Built 1987 Load: 32.7 t ADT: 687

IA 150

Fair

Over: WAPSIPINICON RIVER

IN INDEPENDENCE, Buchanan, IA

Built 1927 Load: 32.7 t ADT: 9,000

DANIAL AVE

Fair

Over: MUD CR

087101602, Buchanan, IA

Built 1989 Load: 32.7 t ADT: 73

270TH ST

Fair

Over: LIME CREEK

088103501, Buchanan, IA

Built 2015 Load: 32.7 t ADT: 30

LOCAL

Fair

Over: OTTER CREEK

090091603, Buchanan, IA

Built 1997 Load: 32.7 t ADT: 295

LOCAL

Fair

Over: MAPLE RIVER

090383001, Buena Vista, IA

Built 1984 Load: 32.7 t ADT: 26

FM

Fair

Over: SM STREAM

091381702, Buena Vista, IA

Built 1974 Load: 32.7 t ADT: 469

LOCAL

Fair

Over: DRAINAGE DITCH

092380702, Buena Vista, IA

Built 1996 Load: 32.7 t ADT: 30

LOCAL

Fair

Over: MAPLE CREEK

092381701, Buena Vista, IA

Built 1984 Load: 32.7 t ADT: 20

FM

Fair

Over: STREAM

093381303, Buena Vista, IA

Built 1973 Load: 32.7 t ADT: 45

FM

Fair

Over: SM STREAM

093383202, Buena Vista, IA

Built 1974 Load: 32.7 t ADT: 688

LOCAL

Fair

Over: BOYER CREEK

090373502, Buena Vista, IA

Built 1993 Load: 32.7 t ADT: 15

FM

Fair

Over: STREAM

091182101, Butler, IA

Built 1993 Load: 32.7 t ADT: 44

FM

Fair

Over: CROOKED CREEK

087340604, Calhoun, IA

Built 1982 Load: 32.7 t ADT: 1,067

LOCAL

Fair

Over: DD#6

088330704, Calhoun, IA

Built 1974 Load: 32.7 t ADT: 45

LOCAL

Fair

Over: D.D.

088341101, Calhoun, IA

Built 1977 Load: 32.7 t ADT: 11

FM

Fair

Over: DD NO. 976

089341901, Calhoun, IA

Built 1938 Load: 32.7 t ADT: 219

LOCAL

Fair

Over: DRAINAGE DITCH 125

090313601, Calhoun, IA

Built 1900 Load: 32.7 t ADT: 60

LOCAL

Fair

Over: FIELD STREAM

083360902, Carroll, IA

Built 1996 Load: 32.7 t ADT: 20

LOCAL - 540TH

Fair

Over: WATERWAY

074370606, Cass, IA

Built 1991 Load: 32.7 t ADT: 72

LOCAL - QUINCY

Fair

Over: STREAM

075342801, Cass, IA

Built 2002 Load: 32.7 t ADT: 30

LOCAL - 720TH

Fair

Over: CREEK

076341804, Cass, IA

Built 1997 Load: 32.7 t ADT: 15

LOCAL/658TH LN

Fair

Over: CREEK

077360104, Cass, IA

Built 1997 Load: 32.7 t ADT: 15

300TH ST (LWC)

Fair

Over: CROOKED CR

079020807, Cedar, IA

Built 1998 Load: 32.7 t ADT: 11

FM

Fair

Over: SMALL STREAM

080030603, Cedar, IA

Built 1993 Load: 32.7 t ADT: 710

FM

Fair

Over: CROOKED CREEK

080031203, Cedar, IA

Built 1989 Load: 32.7 t ADT: 330

TAYLOR RD

Fair

Over: STREAM

082011003, Cedar, IA

Built 1999 Load: 32.7 t ADT: 26

Showing 6,351-6,400 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.