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

50TH ST

Good

Over: LITTLE WAPSI RIVER

091101601, Fayette, IA

Built 2000 Load: 20.9 t ADT: 59

WILLOW RD

Good

Over: LITTLE TURKEY RIVER

095100506, Fayette, IA

Built 1999 Load: 20.9 t ADT: 44

SPRUCE RD

Good

Over: CRANE CREEK

095103603, Fayette, IA

Built 2002 Load: 20.9 t ADT: 20

LOCAL

Good

Over: STREAM

076121608, Keokuk, IA

Built 2006 Load: 20.9 t ADT: 15

SHIMEK ST FOREST

Good

Over: STREAM

1.1 mi. N of Jct. Iowa 2, Lee, IA

Built 1997 Load: 20.9 t

140TH ST

Good

Over: KEIGLEY BRANCH

085242701, Story, IA

Built 1977 Load: 20.9 t ADT: 34

260TH ST

Good

Over: GIZZARD CREEK

094140603, Chickasaw, IA

Built 2000 Load: 21.0 t ADT: 29

LOCAL

Good

Over: EMMIGRANT CREEK

084412502, Crawford, IA

Built 1976 Load: 21.0 t ADT: 91

LOCAL

Good

Over: WELDON RIVER

068240403, Decatur, IA

Built 1997 Load: 21.0 t ADT: 5

LOCAL ROAD

Good

Over: INDIAN CREEK

073392901, Montgomery, IA

Built 1977 Load: 21.0 t ADT: 20

LOCAL

Good

Over: FLOYD RIVER

097422101, O'Brien, IA

Built 1954 Load: 21.0 t ADT: 35

EVERGREEN AVE

Good

Over: INDIAN CREEK

093470704, Plymouth, IA

Built 1996 Load: 21.0 t ADT: 5

FM

Good

Over: FOUR MILE CREEK

081240901, Polk, IA

Built 1975 Load: 21.0 t ADT: 259

DOVE AVE

Good

Over: SMALL STREAM

094463002, Sioux, IA

Built 2021 Load: 21.0 t ADT: 15

GREENHILL RD

Good

Over: SW BR DRY RUN CREEK

0.1 MI S OF UNIV. AVE, Black Hawk, IA

Built 2002 Load: 21.1 t ADT: 143

6TH ST. S.E.

Good

Over: SMALL STREAM

6TH ST SE - SMALL STREAM, Dubuque, IA

Built 1987 Load: 21.1 t ADT: 349

FM

Good

Over: CREEK

087E42407, Jackson, IA

Built 2004 Load: 21.1 t ADT: 150

ACCESS ROAD

Good

Over: STREAM

0.1 mi. S of S.R. C80, Plymouth, IA

Built 2000 Load: 21.1 t ADT: 1,347

LOCAL

Good

Over: STREAM

068302401, Ringgold, IA

Built 2001 Load: 21.1 t ADT: 29

WILDWOOD RD

Good

Over: INDIAN CREEK

079373602, Shelby, IA

Built 2015 Load: 21.1 t ADT: 62

LOCAL

Good

Over: BUCK CREEK

078362204, Audubon, IA

Built 1985 Load: 21.2 t ADT: 15

LOCAL

Good

Over: INDIAN CREEK

079362102, Audubon, IA

Built 1984 Load: 21.2 t ADT: 41

FM

Good

Over: DAVIDS CREEK

080342502, Audubon, IA

Built 1979 Load: 21.2 t ADT: 26

FM N-14

Good

Over: TRIB OF WEST NISHNABOTNA

081362602, Audubon, IA

Built 1980 Load: 21.2 t ADT: 60

LOCAL

Good

Over: STREAM

094111702, Chickasaw, IA

Built 1981 Load: 21.2 t ADT: 62

LOC 230TH AVE

Good

Over: NORTH BUFFALO CREEK

098272602, Kossuth, IA

Built 1984 Load: 21.2 t ADT: 35

LOC 440TH ST

Good

Over: UNION SLOUGH DITCH

099281401, Kossuth, IA

Built 1977 Load: 21.2 t ADT: 5

LOC 470TH ST

Good

Over: UNION SLOUGH DITCH

100283501, Kossuth, IA

Built 1981 Load: 21.2 t ADT: 21

LOCAL

Good

Over: LITTLE CEDAR CREEK

069070901, Lee, IA

Built 1974 Load: 21.2 t ADT: 26

YELLOWSTONE AVE

Good

Over: CREEK

067321202, Taylor, IA

Built 2020 Load: 21.2 t ADT: 40

LOCAL

Good

Over: WHITE FOX CREEK

090252401, Wright, IA

Built 1983 Load: 21.2 t ADT: 15

FM

Good

Over: PLYMOUTH CREEK

092441602, Plymouth, IA

Built 1975 Load: 21.3 t ADT: 789

LOCAL

Good

Over: MIDDLE RACCOON RIVER

084350502, Carroll, IA

Built 1973 Load: 21.4 t ADT: 34

FM

Good

Over: PURGATORY CREEK

085330102, Carroll, IA

Built 1972 Load: 21.4 t ADT: 26

FM

Good

Over: STORM CREEK

085343202, Carroll, IA

Built 1984 Load: 21.4 t ADT: 1,146

325TH ST

Good

Over: SMALL STREAM

087062703, Delaware, IA

Built 2020 Load: 21.4 t ADT: 26

RAINBOW RD

Good

Over: ELK CREEK

090041403, Delaware, IA

Built 2004 Load: 21.4 t ADT: 29

MITCHELL MILL RD

Good

Over: TETE DES MORTS RIVER

088E33204, Dubuque, IA

Built 2016 Load: 21.4 t ADT: 34

SLEEPY HOLLOW RD

Good

Over: CREEK

090E22805, Dubuque, IA

Built 2016 Load: 21.4 t ADT: 50

170TH ST.

Good

Over: KITTY CREEK

085031801, Jones, IA

Built 1988 Load: 21.4 t ADT: 41

HARD SCRABBLE

Good

Over: SILVER CREEK

086030804, Jones, IA

Built 1983 Load: 21.4 t ADT: 137

IA 9

Good

Over: STREAM

0.2 mi. W of IA 182, Lyon, IA

Built 1980 Load: 21.4 t ADT: 4,840

SILVER AVE

Good

Over: NELSON CREEK

09440180210, O'Brien, IA

Built 2016 Load: 21.4 t ADT: 45

190TH ST

Good

Over: DRAINAGE

092432401, Plymouth, IA

Built 1975 Load: 21.4 t ADT: 11

FM

Good

Over: BRANCH OF BIG CREEK

081250903, Polk, IA

Built 1971 Load: 21.4 t ADT: 79

470TH STREET

Good

Over: SECOND CREEK

076392402, Pottawattamie, IA

Built 1985 Load: 21.4 t ADT: 20

390TH STREET

Good

Over: DRAINAGE

076402704, Pottawattamie, IA

Built 2006 Load: 21.4 t ADT: 5

PINE CREEK RD

Good

Over: PINE CREEK

0.6 MI S of Lost Mile Rd, Winneshiek, IA

Built 2016 Load: 21.4 t ADT: 26

IA 9

Good

Over: SPRING CREEK

1.9 MI. W OF US 65, Worth, IA

Built 1994 Load: 21.4 t ADT: 1,470

MARCH ST

Good

Over: CREEK

095161902, Floyd, IA

Built 2007 Load: 21.5 t ADT: 15

Showing 9,251-9,300 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.