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

E18/130TH ST

Fair

Over: MIDDLE MINERVA CREEK

085211901, Story, IA

Built 1973 Load: 42.9 t ADT: 638

LOCAL

Fair

Over: CREEK

068090404, Van Buren, IA

Built 1988 Load: 42.9 t ADT: 73

LOCAL

Fair

Over: STREAM

068090506, Van Buren, IA

Built 1987 Load: 42.9 t ADT: 11

FM

Fair

Over: WINNEBAGO RIVER

095181508, Floyd, IA

Built 1900 Load: 43.0 t ADT: 697

175TH ST

Fair

Over: FARMERS CREEK

085E30705, Jackson, IA

Built 2000 Load: 43.0 t ADT: 30

FM

Fair

Over: DUTCH CREEK

076093102, Washington, IA

Built 1956 Load: 43.0 t ADT: 890

LOCAL

Fair

Over: MUD CREEK

084111601, Benton, IA

Built 1996 Load: 43.1 t ADT: 15

IA 92

Fair

Over: SOUTH SKUNK RIVER

2.2 MI. W OF W JCT SR V13, Mahaska, IA

Built 1985 Load: 43.1 t ADT: 2,850

IA 83

Fair

Over: NATURAL CREEK

0.8 mi. E of Jct. U.S. 59, Pottawattamie, IA

Built 1990 Load: 43.1 t ADT: 790

MAHOGANY ROAD

Fair

Over: STREAM

076421401, Pottawattamie, IA

Built 1979 Load: 43.1 t ADT: 40

NB I-35

Fair

Over: LONG DICK CREEK

0.5 MILES N OF SR E18, Story, IA

Built 1967 Load: 43.1 t ADT: 14,850

SB I-35

Fair

Over: DRAINAGE DITCH #29

1.3 mi N of SR C70, Wright, IA

Built 1974 Load: 43.1 t ADT: 8,250

LOCAL (LWC)

Fair

Over: BR PRAIRIE CK

083111704, Benton, IA

Built 1991 Load: 43.2 t ADT: 5

FM

Fair

Over: WOLF CREEK

087183501, Grundy, IA

Built 1964 Load: 43.2 t ADT: 98

MARKET AVE

Fair

Over: SOLDIER RIVER

086392902, Ida, IA

Built 2000 Load: 43.2 t ADT: 26

LOCAL RD

Fair

Over: BRANCH BLACKHAWK CREEK

089162401, Grundy, IA

Built 1957 Load: 43.3 t ADT: 29

US 61 NB

Fair

Over: BNSF RR

3.9 MI. N OF JCT. US 218, Lee, IA

Built 1999 Load: 43.3 t ADT: 3,500

SB I-29

Fair

Over: KEG CREEK

0.7 MI. S OF S JCT. US 34, Mills, IA

Built 1971 Load: 43.3 t ADT: 6,850

LOCAL SEC RD

Fair

Over: LANGE CREEK NORTH

094422402, O'Brien, IA

Built 1998 Load: 43.3 t ADT: 26

LOCAL

Fair

Over: OTTER CREEK

098422802, Osceola, IA

Built 1986 Load: 43.3 t ADT: 103

1 ST AVE. W

Fair

Over: N FORK MAQUOKETA RIVER

000000000, Dubuque, IA

Built 1979 Load: 43.4 t ADT: 5,495

US 218 SB

Fair

Over: BIG CREEK

3.0 mi. S of S Jct. US 34, Henry, IA

Built 2003 Load: 43.4 t ADT: 4,850

SPRUCE AVE

Fair

Over: ROCK BRANCH

073083101, Jefferson, IA

Built 1950 Load: 43.4 t ADT: 50

SW BLK DIAMOND

Fair

Over: OLD WOMAN'S CREEK

079072705, Johnson, IA

Built 2006 Load: 43.4 t ADT: 650

LOCAL

Fair

Over: CREEK

073170502, Monroe, IA

Built 2001 Load: 43.4 t ADT: 15

FM NE 46TH ST

Fair

Over: MUCHIKINOCK CREEK

080233402, Polk, IA

Built 1990 Load: 43.4 t ADT: 270

FM

Fair

Over: ELLIOTT CREEK

089451001, Woodbury, IA

Built 1969 Load: 43.4 t ADT: 709

FM

Fair

Over: TRIB GRAND RIVER

068262302, Decatur, IA

Built 1957 Load: 43.5 t ADT: 34

X AVE

Fair

Over: WEST BEAVER CREEK

083290104, Greene, IA

Built 1976 Load: 43.5 t ADT: 62

LOCAL

Fair

Over: BIG CEDAR CREEK

090343301, Pocahontas, IA

Built 1971 Load: 43.5 t ADT: 50

LOCAL

Fair

Over: CREEK

078342904, Audubon, IA

Built 1940 Load: 43.6 t ADT: 21

LOCAL

Fair

Over: SMALL CREEK

084E31503, Jackson, IA

Built 2003 Load: 43.6 t ADT: 110

US 75 NB

Fair

Over: FLOYD RIVER

5.3 mi. N of jct. IA 12, Woodbury, IA

Built 2000 Load: 43.6 t ADT: 5,650

W 4TH ST

Fair

Over: CEDAR RIVER

CITY BRIDGE NO. 34, Black Hawk, IA

Built 1975 Load: 43.7 t ADT: 1,908

LOCAL

Fair

Over: MONTGOMERY CREEK

085263601, Boone, IA

Built 1994 Load: 43.7 t ADT: 30

US 67

Fair

Over: SHADDUCKS CREEK

5.7 mi. N of N Jct IA 136, Clinton, IA

Built 1967 Load: 43.7 t ADT: 2,170

LOCAL

Fair

Over: FLINT CREEK

070031607, Des Moines, IA

Built 1983 Load: 43.7 t ADT: 390

BUNCOMBE RD

Fair

Over: BUNCOMBE CREEK

087E21403, Dubuque, IA

Built 2001 Load: 43.7 t ADT: 34

LOCAL

Fair

Over: BUNCOMBE CREEK

087E21504, Dubuque, IA

Built 1993 Load: 43.7 t ADT: 20

IA 38

Fair

Over: WALNUT CREEK

0.3 mi. S of S jct SR E45, Jones, IA

Built 1977 Load: 43.7 t ADT: 1,550

FM

Fair

Over: BUCK CREEK

078153005, Poweshiek, IA

Built 1977 Load: 43.7 t ADT: 60

LOCAL

Fair

Over: STREAM

078161504, Poweshiek, IA

Built 1977 Load: 43.7 t ADT: 80

W RIVERSIDE RD

Fair

Over: SKUNK RIVER

084242207, Story, IA

Built 1989 Load: 43.7 t ADT: 3,301

BLUEBILL AVE

Fair

Over: ELK CREEK

099220506, Worth, IA

Built 2001 Load: 43.7 t ADT: 187

LOCAL

Fair

Over: CREEK

086203501, Hardin, IA

Built 1989 Load: 43.8 t ADT: 16

FM

Fair

Over: ROCKY RUN

083380403, Crawford, IA

Built 1974 Load: 43.9 t ADT: 79

OAK HILL AVE

Fair

Over: LITTLE FLOYD RIVER

96240201, O'Brien, IA

Built 2020 Load: 43.9 t ADT: 26

US 67

Fair

Over: CROW CREEK

5.2 mi. S of Jct. I-80, Scott, IA

Built 1996 Load: 43.9 t ADT: 9,800

150TH ST

Fair

Over: QUARTER SECTION RUN

093133301, Bremer, IA

Built 1954 Load: 44.0 t ADT: 49

SB I-35

Fair

Over: BEAVER DAM CREEK

0.6 MI. S OF JCT. SR B43, Cerro Gordo, IA

Built 1972 Load: 44.0 t ADT: 8,900

Showing 8,351-8,400 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.