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

FM

Fair

Over: TOOLE CREEK

100461901, Lyon, IA

Built 1979 Load: 33.4 t ADT: 45

S ODELL AVE

Fair

Over: STREAM

081900500, Madison, IA

Built 1962 Load: 33.4 t ADT: 235

240TH PLACE

Fair

Over: SKUNK RIVER OVERFLOW

077181403, Marion, IA

Built 1946 Load: 33.4 t ADT: 220

LOCAL

Fair

Over: N BR 102 RIVER

070342004, Taylor, IA

Built 1996 Load: 33.4 t ADT: 20

LOCAL

Fair

Over: SMALL STREAM

072280203, Union, IA

Built 1979 Load: 33.4 t ADT: 11

FM

Fair

Over: MIDDLE NODAWAY RIVER BR.

076330502, Adair, IA

Built 1993 Load: 33.5 t ADT: 45

130TH ST

Fair

Over: STREAM

092120601, Bremer, IA

Built 2001 Load: 33.5 t ADT: 108

LOCAL

Fair

Over: LITTLE TURKEY

096112505, Chickasaw, IA

Built 1975 Load: 33.5 t ADT: 25

BACKBONE STATE PK

Fair

Over: BR MAQUOKETA RIVER

IN BACKBONE STATE PARK, Delaware, IA

Built 1976 Load: 33.5 t

FM

Fair

Over: DES MOINES RIVER

0983307, Emmet, IA

Built 1976 Load: 33.5 t ADT: 390

QUEBEC PLACE

Fair

Over: WILLOW RIVER

081420903, Harrison, IA

Built 1975 Load: 33.5 t ADT: 11

FM

Fair

Over: BIG CREEK

072062904, Henry, IA

Built 1980 Load: 33.5 t ADT: 230

PRAIRIEBURG RD

Fair

Over: BUFFALO CREEK

085050306, Linn, IA

Built 1974 Load: 33.5 t ADT: 520

H32 245TH TRL

Fair

Over: UP RR

072212005, Lucas, IA

Built 1982 Load: 33.5 t ADT: 490

FM

Fair

Over: LITTLE CREEK

077172216, Mahaska, IA

Built 1967 Load: 33.5 t ADT: 1,130

FM-360TH ST

Fair

Over: DEER CREEK

071403002, Mills, IA

Built 1979 Load: 33.5 t ADT: 110

IA 22

Fair

Over: PINE CREEK

0.1 mi east of SR Y-26, Muscatine, IA

Built 1973 Load: 33.5 t ADT: 1,490

FM

Fair

Over: SWEETLAND CREEK

077011501, Muscatine, IA

Built 1937 Load: 33.5 t ADT: 80

FM

Fair

Over: OCHEYEDAN RIVER

098390828, Osceola, IA

Built 1976 Load: 33.5 t ADT: 219

EASTER LK PK

Fair

Over: STREAM

000000000, Polk, IA

Built 1968 Load: 33.5 t

FM RD F32

Fair

Over: MOSQUITO CREEK

802640, Shelby, IA

Built 1974 Load: 33.5 t ADT: 816

LOCAL

Fair

Over: SMALL STREAM

092253401, Wright, IA

Built 1996 Load: 33.5 t ADT: 51

LOCAL

Fair

Over: SMALL STREAM

085102404, Benton, IA

Built 1991 Load: 33.6 t ADT: 49

LOCAL

Fair

Over: BIG CREEK

083252002, Boone, IA

Built 1900 Load: 33.6 t ADT: 40

IA 14

Fair

Over: W FK CEDAR RIVER

4.9 MI. S OF JCT. IA 3, Butler, IA

Built 1984 Load: 33.6 t ADT: 1,160

15TH ST SW

Fair

Over: CHESLEA CREEK

000000000, Cerro Gordo, IA

Built 1980 Load: 33.6 t ADT: 2,567

FM

Fair

Over: DEVILS RUN

079112906, Iowa, IA

Built 1975 Load: 33.6 t ADT: 320

FM

Fair

Over: HOG RUN

079111206, Iowa, IA

Built 1975 Load: 33.6 t ADT: 120

CO RD H22

Fair

Over: SMALL STREAM

073022801, Louisa, IA

Built 1959 Load: 33.6 t ADT: 440

170TH ST

Fair

Over: ARGO SLOUGH

99431601, Lyon, IA

Built 2017 Load: 33.6 t ADT: 11

NEW HIGHLAND AC

Fair

Over: UP RR

083180400, Marshall, IA

Built 2008 Load: 33.6 t ADT: 1,738

325TH

Fair

Over: SMALL STREAM

097181203, Mitchell, IA

Built 1985 Load: 33.6 t ADT: 29

CAMEO AVE

Fair

Over: CREEK

098182102, Mitchell, IA

Built 1920 Load: 33.6 t ADT: 26

480TH ST

Fair

Over: CREEK

100162505, Mitchell, IA

Built 1970 Load: 33.6 t ADT: 44

IA 37

Fair

Over: BEAVER CREEK

4.4 mi. E of IA 175, Monona, IA

Built 1942 Load: 33.6 t ADT: 780

US 59

Fair

Over: STREAM

2.4 MI. N OF JCT. 92, Pottawattamie, IA

Built 1930 Load: 33.6 t ADT: 1,990

WB I-80

Fair

Over: KEG CREEK

0.8 MI. E OF JCT. SR L66, Pottawattamie, IA

Built 1966 Load: 33.6 t ADT: 13,200

LOCAL

Fair

Over: LONG BRANCH CREEK

080370301, Shelby, IA

Built 1950 Load: 33.6 t ADT: 30

US 63

Fair

Over: BROWN CREEK

1.9 mi. S of jct. IA 137, Wapello, IA

Built 1988 Load: 33.6 t ADT: 9,900

LOCAL

Fair

Over: BUTCHER CREEK

077232604, Warren, IA

Built 1985 Load: 33.6 t ADT: 26

LOCAL

Fair

Over: RUFT BRANCH

075331105, Adair, IA

Built 2007 Load: 33.7 t ADT: 21

220TH ST

Fair

Over: SMALL NATURAL STREAM

088100615, Buchanan, IA

Built 1999 Load: 33.7 t ADT: 2,494

LOCAL

Fair

Over: SMALL STREAM

090181801, Butler, IA

Built 1941 Load: 33.7 t ADT: 26

LOCAL

Fair

Over: SUGAR CREEK

079020301, Cedar, IA

Built 1978 Load: 33.7 t ADT: 31

300TH AVE

Fair

Over: STREAM

096352102, Clay, IA

Built 1999 Load: 33.7 t ADT: 46

120TH AVE.

Fair

Over: CREEK

082E12802, Clinton, IA

Built 1920 Load: 33.7 t ADT: 21

LOCAL

Fair

Over: SMALL STREAM

078283603, Dallas, IA

Built 1954 Load: 33.7 t ADT: 807

PK 678(VOLGA R)

Fair

Over: FROG HOLLOW CREEK

IN VOLGA RIVER ST.PARK, Fayette, IA

Built 1957 Load: 33.7 t

FM

Fair

Over: SLOUGH CREEK

097151902, Floyd, IA

Built 1987 Load: 33.7 t ADT: 59

110TH ST

Fair

Over: LITTLE CEDAR RIVER

097162503, Floyd, IA

Built 1977 Load: 33.7 t ADT: 78

Showing 7,301-7,350 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.