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 ROAD

Good

Over: ARGO SLOUGH

099431102, Lyon, IA

Built 1900 Load: 28.6 t ADT: 26

US 65

Good

Over: MUD CREEK

IN BONDURANT, Polk, IA

Built 1974 Load: 28.6 t ADT: 13,800

16TH AVE

Good

Over: INDIAN CREEK

000000000, Pottawattamie, IA

Built 1995 Load: 28.6 t ADT: 2,033

B62

Good

Over: SMALL

094473501, Sioux, IA

Built 1978 Load: 28.6 t ADT: 30

LOCAL

Good

Over: FLOYD RIVER

095432005, Sioux, IA

Built 1940 Load: 28.6 t ADT: 30

LOCAL

Good

Over: NODAWAY CREEK

076323602, Adair, IA

Built 2007 Load: 28.7 t ADT: 41

FM

Good

Over: CREEK

078360404, Audubon, IA

Built 1939 Load: 28.7 t ADT: 60

300TH ST

Good

Over: SMALL

079031801, Cedar, IA

Built 2005 Load: 28.7 t ADT: 35

250TH ST

Good

Over: MUNNS CREEK

087162201, Grundy, IA

Built 2006 Load: 28.7 t ADT: 11

FM RD F16

Good

Over: MOSER CREEK

081390901, Shelby, IA

Built 1994 Load: 28.7 t ADT: 60

92ND ST

Good

Over: BUCKEYE CREEK

072122103, Wapello, IA

Built 2010 Load: 28.7 t ADT: 21

FM F-58

Good

Over: CREEK

078343404, Audubon, IA

Built 2007 Load: 28.8 t ADT: 278

WELLMAN RD

Good

Over: SPRING CREEK

87-11-11-03-10, Black Hawk, IA

Built 1983 Load: 28.8 t ADT: 29

US 218

Good

Over: DRAINAGE DITCH

0.4 mi. N of Jct. IA #188, Bremer, IA

Built 2001 Load: 28.8 t ADT: 7,900

US 71

Good

Over: STREAM

0.1 mi. N of SR E46, Carroll, IA

Built 1985 Load: 28.8 t ADT: 3,350

LOCAL

Good

Over: FIELD STREAM

083363504, Carroll, IA

Built 2004 Load: 28.8 t ADT: 11

205TH STREET

Good

Over: ROCK CR

081032705, Cedar, IA

Built 2005 Load: 28.8 t ADT: 40

CHARLES AVE

Good

Over: BR CLEAR CR

082042102, Cedar, IA

Built 2011 Load: 28.8 t ADT: 80

180TH STREET

Good

Over: STREAM

081021301, Cedar, IA

Built 2006 Load: 28.8 t ADT: 20

120TH

Good

Over: COLD WATER CREEK

094192701, Cerro Gordo, IA

Built 1985 Load: 28.8 t ADT: 11

BALSAM

Good

Over: WINNEBAGO RIVER

097222002, Cerro Gordo, IA

Built 1969 Load: 28.8 t ADT: 815

NB US 61

Good

Over: SILVER CREEK

0.5 MI.S.OF JCT.US 30, Clinton, IA

Built 1981 Load: 28.8 t ADT: 7,050

LOCAL 125 AVE

Good

Over: SMALL STREAM

087060904, Delaware, IA

Built 1990 Load: 28.8 t ADT: 29

U AVE

Good

Over: STOE CREEK

092101102, Fayette, IA

Built 2007 Load: 28.8 t ADT: 33

I 35

Good

Over: STREAM

0.3 MILE NORTH OF SR D65, Hamilton, IA

Built 1965 Load: 28.8 t ADT: 26,800

IA 224

Good

Over: COON CREEK

0.8 MI NORTH OF JCT US 6, Jasper, IA

Built 1992 Load: 28.8 t ADT: 850

FREMONT RD.

Good

Over: BUFFALO CREEK

085043004, Jones, IA

Built 1985 Load: 28.8 t ADT: 98

SB I-380

Good

Over: OVER UP RR

1.0 MI. N OF JCT. US 30, Linn, IA

Built 1974 Load: 28.8 t ADT: 31,400

FM

Good

Over: WHITE BREAST CREEK

074210404, Marion, IA

Built 1977 Load: 28.8 t ADT: 40

IA 48

Good

Over: FISHBAUGH DITCH

2.2 MI. N OF JCT. 59, Page, IA

Built 1969 Load: 28.8 t ADT: 2,430

195TH STREET

Good

Over: FLOYD RIVER

092451907, Plymouth, IA

Built 1975 Load: 28.8 t ADT: 60

FAWN AVE

Good

Over: INDIAN CREEK

093471702, Plymouth, IA

Built 1900 Load: 28.8 t ADT: 34

FM

Good

Over: SKUNK RIVER

080222402, Polk, IA

Built 1961 Load: 28.8 t ADT: 588

LOCAL

Good

Over: CREEK

079343104, Audubon, IA

Built 2001 Load: 28.9 t ADT: 30

W AIRLINE HWY

Good

Over: NO NAME CREEK

CITY BRIDGE NO. 26, Black Hawk, IA

Built 2001 Load: 28.9 t ADT: 4,594

US 18

Good

Over: STREAM

0.2 mi. E of E Jct. US 63, Chickasaw, IA

Built 2001 Load: 28.9 t ADT: 2,610

IA 21

Good

Over: NORTH SKUNK RIVER

0.7 MI. S OF DELTA, Keokuk, IA

Built 1988 Load: 28.9 t ADT: 830

FM

Good

Over: LITTLE OCHEYEDAN RIVER

098401002, Osceola, IA

Built 1964 Load: 28.9 t ADT: 100

LOCAL

Good

Over: BRANCH WEASEL CREEK

082100702, Benton, IA

Built 1987 Load: 29.0 t ADT: 30

245TH ST

Good

Over: SMALL STREAM

091171403, Butler, IA

Built 2013 Load: 29.0 t ADT: 62

FM

Good

Over: FIELD STREAM

082363202, Carroll, IA

Built 1994 Load: 29.0 t ADT: 767

FM

Good

Over: SUGAR CREEK

078261607, Dallas, IA

Built 1986 Load: 29.0 t ADT: 976

FM

Good

Over: BATTLE CREEK

088413501, Ida, IA

Built 1981 Load: 29.0 t ADT: 40

S 60TH AVE E

Good

Over: ELK CREEK

079182803, Jasper, IA

Built 1998 Load: 29.0 t ADT: 41

TOWER TERR.RD.

Good

Over: OTTER CREEK

084082409, Linn, IA

Built 1984 Load: 29.0 t ADT: 1,237

440TH

Good

Over: SMALL STREAM

099161501, Mitchell, IA

Built 1986 Load: 29.0 t ADT: 11

500TH ST

Good

Over: DOG CREEK

0943934, O'Brien, IA

Built 2009 Load: 29.0 t ADT: 10

FM C-44

Good

Over: JOHN'S CREEK

091442401, Plymouth, IA

Built 1985 Load: 29.0 t ADT: 150

FM

Good

Over: DEEP CREEK

093433202, Plymouth, IA

Built 1981 Load: 29.0 t ADT: 868

FM

Good

Over: INDIAN CREEK

074392402, Pottawattamie, IA

Built 1981 Load: 29.0 t ADT: 20

Showing 9,901-9,950 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.