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

270TH ST

Good

Over: PERRY CREEK

091473501, Plymouth, IA

Built 1986 Load: 30.6 t ADT: 80

LILAC AVE

Good

Over: ELK CREEK

099212406, Worth, IA

Built 1972 Load: 30.6 t ADT: 82

LOCAL

Good

Over: FIELD STREAM

084350802, Carroll, IA

Built 1990 Load: 30.7 t ADT: 45

B 66 (290TH ST)

Good

Over: WAPSIPINICON

094132501, Chickasaw, IA

Built 2013 Load: 30.7 t ADT: 49

LOCAL

Good

Over: SQUAW CREEK

073251101, Clarke, IA

Built 2002 Load: 30.7 t ADT: 11

200TH AVENUE

Good

Over: CREEK

083E21102, Clinton, IA

Built 1993 Load: 30.7 t ADT: 21

135TH ST.

Good

Over: SPRING CREEK

083E62105, Clinton, IA

Built 1990 Load: 30.7 t ADT: 47

MILL STREET

Good

Over: S RACCOON RIVER

078272206, Dallas, IA

Built 2007 Load: 30.7 t ADT: 2,872

FM

Good

Over: CRANE CREEK

095103105, Fayette, IA

Built 1980 Load: 30.7 t ADT: 69

NW BAXTER AVE

Good

Over: KNAPP CREEK

081080604, Johnson, IA

Built 1995 Load: 30.7 t ADT: 15

IA 92

Good

Over: OLD DES MOINES RIVER CHL

2.6 MI. E OF S.R. T17, Marion, IA

Built 1978 Load: 30.7 t ADT: 3,240

FM

Good

Over: SOUTH CHARITON RIVER

069201006, Wayne, IA

Built 1969 Load: 30.7 t ADT: 310

SPRING CREEK RD

Good

Over: TRIB TO SPRING CREEK

88-11-12-10-10, Black Hawk, IA

Built 1985 Load: 30.8 t ADT: 196

FM

Good

Over: RACCOON RIVER D.D.#34

092362101, Buena Vista, IA

Built 1986 Load: 30.8 t ADT: 60

215TH AVE

Good

Over: CREEK

081E22404, Clinton, IA

Built 1992 Load: 30.8 t ADT: 51

FM

Good

Over: BOYER RIVER

083391609, Crawford, IA

Built 1975 Load: 30.8 t ADT: 131

DOGWOOD AVE

Good

Over: IOWA RIVER

090222704, Franklin, IA

Built 1976 Load: 30.8 t ADT: 88

QUAIL AVE

Good

Over: SPRING CREEK

092202602, Franklin, IA

Built 1984 Load: 30.8 t ADT: 73

FM

Good

Over: MOSQUITO CREEK

087153101, Grundy, IA

Built 1981 Load: 30.8 t ADT: 44

FM

Good

Over: MOSQUITO CREEK

087163602, Grundy, IA

Built 1983 Load: 30.8 t ADT: 39

LOCAL

Good

Over: BRUSH CREEK

072082706, Jefferson, IA

Built 1987 Load: 30.8 t ADT: 30

LOCAL

Good

Over: SMITH CREEK

073033602, Louisa, IA

Built 1984 Load: 30.8 t ADT: 60

FM

Good

Over: RAT CREEK

098433301, Lyon, IA

Built 2008 Load: 30.8 t ADT: 50

FM-KEYS AVE

Good

Over: SILVER CREEK

072413005, Mills, IA

Built 1978 Load: 30.8 t ADT: 120

SHADOW AVE

Good

Over: BURR OAK CREEK

098161204, Mitchell, IA

Built 1974 Load: 30.8 t ADT: 59

440TH

Good

Over: TURTLE CREEK

099171801, Mitchell, IA

Built 1975 Load: 30.8 t ADT: 49

LOCAL

Good

Over: CREEK

090433004, Plymouth, IA

Built 1984 Load: 30.8 t ADT: 589

FM C-60

Good

Over: MINNIE BROOK

090450703, Plymouth, IA

Built 1979 Load: 30.8 t ADT: 628

LYNX AVENUE

Good

Over: SMALL STREAM

092453302, Plymouth, IA

Built 1987 Load: 30.8 t ADT: 50

FM

Good

Over: BIG CEDAR CREEK D.D.#41

092340202, Pocahontas, IA

Built 1986 Load: 30.8 t ADT: 34

LOCAL

Good

Over: PILOT CREEK

093331302, Pocahontas, IA

Built 1980 Load: 30.8 t ADT: 20

FM

Good

Over: INDIAN CREEK

074393405, Pottawattamie, IA

Built 1982 Load: 30.8 t ADT: 11

FM-LOMBARDY RD

Good

Over: SILVER CREEK

076412601, Pottawattamie, IA

Built 1986 Load: 30.8 t ADT: 71

FM

Good

Over: TRIBUTARY MOSQUITO CREEK

80839, Shelby, IA

Built 1980 Load: 30.8 t ADT: 368

FM

Good

Over: UPPER IOWA RIVER

098070803, Winneshiek, IA

Built 1976 Load: 30.8 t ADT: 265

LOCAL

Good

Over: MCELHANEY CREEK

089442301, Woodbury, IA

Built 1982 Load: 30.8 t ADT: 5

US 71

Good

Over: TURKEY CREEK

0.1 MI. N OF SR G-35, Cass, IA

Built 1971 Load: 30.9 t ADT: 2,830

W 88TH ST N

Good

Over: FULLINGTON CREEK

080202004, Jasper, IA

Built 2011 Load: 30.9 t ADT: 41

LOCAL

Good

Over: BRUSH CREEK

071213104, Lucas, IA

Built 2001 Load: 30.9 t ADT: 16

E63 190TH ST

Good

Over: PLUM CREEK

082E11805, Clinton, IA

Built 2020 Load: 31.0 t ADT: 110

IA 7

Good

Over: LIZARD CREEK

0.5 mi. W of Jct. US 169, Webster, IA

Built 1974 Load: 31.0 t ADT: 4,810

FERN BLVD

Good

Over: CARTER CREEK

068151300, Davis, IA

Built 2022 Load: 31.1 t ADT: 11

RUBY BLVD

Good

Over: NORTH CHEQUEST CREEK

070132504, Davis, IA

Built 2022 Load: 31.1 t ADT: 20

EB US 34

Good

Over: BNSF RR

0.3 MI. W OF JCT. US 61, Des Moines, IA

Built 1976 Load: 31.1 t ADT: 5,450

LOCAL

Good

Over: CLEAR CREEK

081201703, Jasper, IA

Built 2003 Load: 31.1 t ADT: 16

467TH (S.FORST)

Good

Over: BR OF WHITEBREAST CREEK

1.8 MI. W OF JCT. US 65, Lucas, IA

Built 1996 Load: 31.1 t ADT: 11

US 6

Good

Over: EAST JORDAN CREEK

5.8 mi. E of E Jct. US 59, Pottawattamie, IA

Built 1991 Load: 31.1 t ADT: 1,120

FM

Good

Over: W NISHNABOTNA RIVER

781039, Shelby, IA

Built 2007 Load: 31.1 t ADT: 409

595TH AVE

Good

Over: SKUNK RIVER

082232203, Story, IA

Built 2002 Load: 31.1 t ADT: 290

LOCAL

Good

Over: BRANCH OF RAVEN CREEK

082160702, Tama, IA

Built 2010 Load: 31.1 t ADT: 26

Showing 10,201-10,250 of 20,753 bridges

Related

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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.