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

Good

Over: BRANCH CEDAR RIVER

094143302, Chickasaw, IA

Built 2001 Load: 32.7 t ADT: 98

220TH ST

Good

Over: SIMPSON CREEK

095112101, Chickasaw, IA

Built 2006 Load: 32.7 t ADT: 20

220TH ST

Good

Over: CREEK

095122401, Chickasaw, IA

Built 2006 Load: 32.7 t ADT: 73

LOCAL

Good

Over: CREEK

095132403, Chickasaw, IA

Built 2000 Load: 32.7 t ADT: 118

LOCAL

Good

Over: SPRING BRANCH

095132409, Chickasaw, IA

Built 2000 Load: 32.7 t ADT: 1,169

LOCAL

Good

Over: CREEK

096111402, Chickasaw, IA

Built 1997 Load: 32.7 t ADT: 62

FM

Good

Over: LITTLE TURKEY

096111407, Chickasaw, IA

Built 2010 Load: 32.7 t ADT: 157

LOCAL

Good

Over: DRY RUN

096112604, Chickasaw, IA

Built 2001 Load: 32.7 t ADT: 62

LOCAL

Good

Over: CREEK

096123004, Chickasaw, IA

Built 2005 Load: 32.7 t ADT: 157

LOCAL

Good

Over: CREEK

096131201, Chickasaw, IA

Built 2010 Load: 32.7 t ADT: 26

LOCAL

Good

Over: E FORK WAPSIPINICON RVR

096131501, Chickasaw, IA

Built 2011 Load: 32.7 t ADT: 26

LOCAL

Good

Over: CREEK

96132303, Chickasaw, IA

Built 2010 Load: 32.7 t ADT: 51

FM

Good

Over: BRANCH WAPSIPINICON RVR

096140901, Chickasaw, IA

Built 1991 Load: 32.7 t ADT: 501

FM

Good

Over: BOHEMIAN CREEK

097112407, Chickasaw, IA

Built 2001 Load: 32.7 t ADT: 972

FM

Good

Over: SPRING CREEK

097122001, Chickasaw, IA

Built 1992 Load: 32.7 t ADT: 246

ODESSA

Good

Over: SMALL

097123404, Chickasaw, IA

Built 2007 Load: 32.7 t ADT: 41

FM

Good

Over: UNNAMED CREEK

097142202, Chickasaw, IA

Built 1997 Load: 32.7 t ADT: 108

LOCAL

Good

Over: BR WASIPINICON RIVER

097142904, Chickasaw, IA

Built 2008 Load: 32.7 t ADT: 26

LOCAL

Good

Over: SMALL STREAM

097122503, Chickasaw, IA

Built 1999 Load: 32.7 t ADT: 16

LOCAL

Good

Over: SMALL STREAM

095110401, Chickasaw, IA

Built 2000 Load: 32.7 t ADT: 41

LOCAL

Good

Over: WEST LONG CREEK

071270503, Clarke, IA

Built 2007 Load: 32.7 t ADT: 11

FREEDOM ST

Good

Over: BR W LONG CR

071270801, Clarke, IA

Built 2018 Load: 32.7 t ADT: 20

LOCAL

Good

Over: SMALL STREAM

072270602, Clarke, IA

Built 2002 Load: 32.7 t ADT: 11

LOCAL

Good

Over: BRANCH OTTER CREEK

073242803, Clarke, IA

Built 2003 Load: 32.7 t ADT: 45

FM

Good

Over: WEST CREEK

073250204, Clarke, IA

Built 2003 Load: 32.7 t ADT: 50

LOCAL

Good

Over: SMALL CREEK

073252101, Clarke, IA

Built 2003 Load: 32.7 t ADT: 60

JIMMY DEAN AVE

Good

Over: DRAINAGE DITCH

072262407, Clarke, IA

Built 2018 Load: 32.7 t ADT: 10

495TH ST

Good

Over: LITTLE SIOUX RIVER

094362803, Clay, IA

Built 2005 Load: 32.7 t ADT: 30

FM 170TH AVE

Good

Over: SMALL WATERWAY

094370802, Clay, IA

Built 1993 Load: 32.7 t ADT: 219

FM 240TH AVE

Good

Over: LITTLE SIOUX RIVER

096361608, Clay, IA

Built 1991 Load: 32.7 t ADT: 2,623

TOLLGATE RD

Good

Over: SMALL STREAM

091012805, Clayton, IA

Built 1982 Load: 32.7 t ADT: 246

MESQUITE RD

Good

Over: SMALL STREAM

091020603, Clayton, IA

Built 1986 Load: 32.7 t ADT: 41

CHERRY VALLEY R

Good

Over: STREAM

091021507, Clayton, IA

Built 1996 Load: 32.7 t ADT: 104

A AVE

Good

Over: STREAM

091060704, Clayton, IA

Built 1996 Load: 32.7 t ADT: 39

ACORN RD

Good

Over: STREAM

091062906, Clayton, IA

Built 2000 Load: 32.7 t ADT: 62

310TH ST

Good

Over: STREAM

1.8 miles S of 300th, Clayton, IA

Built 2018 Load: 32.7 t ADT: 73

290TH ST

Good

Over: STREAM

0.5 miles W of Killdeer A, Clayton, IA

Built 2018 Load: 32.7 t ADT: 21

JOLES HOLLOW RD

Good

Over: JOLES CREEK

0.5 miles E Kale Ave, Clayton, IA

Built 2018 Load: 32.7 t ADT: 29

HEMLOCK RD

Good

Over: STREAM

092041004, Clayton, IA

Built 1999 Load: 32.7 t ADT: 30

EMPIRE RD

Good

Over: STREAM

0.5 miles S 270th St, Clayton, IA

Built 2017 Load: 32.7 t ADT: 35

GLIDER AVE

Good

Over: STREAM

094040706, Clayton, IA

Built 1985 Load: 32.7 t ADT: 73

ARMADA RD

Good

Over: STREAM

1.9 miles N of hwy 56, Clayton, IA

Built 2020 Load: 32.7 t ADT: 21

HAWK AVE

Good

Over: STREAM

1 mile N of Hwy 18, Clayton, IA

Built 2020 Load: 32.7 t ADT: 30

IOWA AVE

Good

Over: SMALL STREAM

091042206, Clayton, IA

Built 2005 Load: 32.7 t ADT: 79

105TH AVE

Good

Over: YANKEE RUN CR

081E10706, Clinton, IA

Built 1971 Load: 32.7 t ADT: 73

230TH ST

Good

Over: BROPHYS CREEK

081E50901, Clinton, IA

Built 1985 Load: 32.7 t ADT: 41

185TH AVENUE

Good

Over: DRAINAGE DITCH #10

082E22104, Clinton, IA

Built 2006 Load: 32.7 t ADT: 26

110TH ST

Good

Over: PRAIRIE CREEK

083E20805, Clinton, IA

Built 2019 Load: 32.7 t ADT: 90

STOCKWELL LN

Good

Over: SMALL STREAM

082062401, Clinton, IA

Built 1994 Load: 32.7 t ADT: 887

LINCOLNWAY

Good

Over: DRAINAGE DITCH

081011000, Clinton, IA

Built 1993 Load: 32.7 t ADT: 340

Showing 11,301-11,350 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.