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

ALDERMAN RD

Good

Over: SIMMENS CREEK

084053402, Linn, IA

Built 1996 Load: 57.9 t ADT: 33

AUSTIN RD

Good

Over: INDAIN CREEK

084060505, Linn, IA

Built 1994 Load: 57.9 t ADT: 70

BIG SPRING RD

Good

Over: CRABAPPLE CREEK

084062301, Linn, IA

Built 1994 Load: 57.9 t ADT: 25

RADIO RD

Good

Over: CRABAPPLE CREEK

084062603, Linn, IA

Built 1995 Load: 57.9 t ADT: 69

JORDANS GRV RD

Good

Over: CRABAPPLE

084062506, Linn, IA

Built 1998 Load: 57.9 t ADT: 246

OTTER RD

Good

Over: WEST OTTER CREEK

084070702, Linn, IA

Built 2006 Load: 57.9 t ADT: 148

HOLLENBECK RD

Good

Over: GANNON CREEK

084082906, Linn, IA

Built 1998 Load: 57.9 t ADT: 97

YATES RD

Good

Over: GANNON CREEK

084083003, Linn, IA

Built 2001 Load: 57.9 t ADT: 15

LINN-BENTON RD

Good

Over: GANNON CREEK

084083102, Linn, IA

Built 2002 Load: 57.9 t ADT: 88

MCNAMARA RD

Good

Over: TRIB BUFFALO CREEK

085050307, Linn, IA

Built 1995 Load: 57.9 t ADT: 59

WAPSIE BANKS RD

Good

Over: TRIB TO WAPSIPINICON

085051603, Linn, IA

Built 1992 Load: 57.9 t ADT: 98

ALDERMAN RD

Good

Over: TRIB WAPSIPINICON RIVER

085052806, Linn, IA

Built 2007 Load: 57.9 t ADT: 33

BURNETT STA.RD.

Good

Over: RICHOHET CREEK

085053001, Linn, IA

Built 1998 Load: 57.9 t ADT: 5

ROWLEY RD

Good

Over: TRIB WAPSIPINICON RIVER

085061008, Linn, IA

Built 2002 Load: 57.9 t ADT: 10

BURNETT STA.RD.

Good

Over: TRIB EAST INDIAN CREEK

085062701, Linn, IA

Built 2003 Load: 57.9 t ADT: 98

LYMAN RD.

Good

Over: E OTTER CR

085070303, Linn, IA

Built 2005 Load: 57.9 t ADT: 29

ALICE RD

Good

Over: TRIB W OTTER CREEK

085070502, Linn, IA

Built 1996 Load: 57.9 t ADT: 137

CUPOLA RD

Good

Over: EAST OTTER CREEK

085071504, Linn, IA

Built 1999 Load: 57.9 t ADT: 70

DEAL RD

Good

Over: W OTTER CREEK,TRIB. TO

085071801, Linn, IA

Built 1997 Load: 57.9 t ADT: 20

DEAL RD

Good

Over: W OTTER CREEK

085071801, Linn, IA

Built 2001 Load: 57.9 t ADT: 20

FOREST EDGE RD

Good

Over: W OTTER CREEK

085071905, Linn, IA

Built 2004 Load: 57.9 t ADT: 59

OLD CENTER RD

Good

Over: E OTTER CREEK

085072103, Linn, IA

Built 2000 Load: 57.9 t ADT: 97

ARABIAN RD

Good

Over: DRY CREEK

085073603, Linn, IA

Built 1991 Load: 57.9 t ADT: 49

ROLLING ACRE RD

Good

Over: EAST BLUE CREEK TRIB TO

085080507, Linn, IA

Built 2002 Load: 57.9 t ADT: 255

ROLLING ACRE RD

Good

Over: EAST BLUE CREEK

085080507, Linn, IA

Built 2002 Load: 57.9 t ADT: 255

QUAIL RIDGE RD

Good

Over: NELSON CREEK

085083503, Linn, IA

Built 1992 Load: 57.9 t ADT: 157

GREENS GROVE RD

Good

Over: NELSON CREEK

085083505, Linn, IA

Built 1991 Load: 57.9 t ADT: 34

CALDWELL RD

Good

Over: BOULDER CREEK

086051602, Linn, IA

Built 2002 Load: 57.9 t ADT: 10

AMMETER RD

Good

Over: TRIB TO BUFFALO CREEK

086051804, Linn, IA

Built 2000 Load: 57.9 t ADT: 11

HILLS MILL RD

Good

Over: BOULDER CREEK

086052004, Linn, IA

Built 2003 Load: 57.9 t ADT: 20

WAGNER RD

Good

Over: CEDAR CREEK

086052106, Linn, IA

Built 2003 Load: 57.9 t ADT: 29

PRAIRIE MAIN RD

Good

Over: CEDAR CREEK

086052905, Linn, IA

Built 2000 Load: 57.9 t ADT: 88

HEATONS VALLEY

Good

Over: TRIB TO HEATONS CREEK

086062303, Linn, IA

Built 1997 Load: 57.9 t ADT: 59

FORD RD

Good

Over: HEATONS CREEK

086063504, Linn, IA

Built 2002 Load: 57.9 t ADT: 59

CAMPFIRE RD

Good

Over: TRIB TO WAPSIPINICON R

086071703, Linn, IA

Built 1997 Load: 57.9 t ADT: 88

WEST OTTER RD

Good

Over: W OTTER CREEK

086073002, Linn, IA

Built 1999 Load: 57.9 t ADT: 29

JUSTINS RD

Good

Over: JUSTINS CREEK

086073603, Linn, IA

Built 2000 Load: 57.9 t ADT: 26

BETTYS GROVE RD

Good

Over: E BLUE CREEK

086081502, Linn, IA

Built 2001 Load: 57.9 t ADT: 128

BETTYS GROVE RD

Good

Over: EAST BLUE CREEK

086082202, Linn, IA

Built 2001 Load: 57.9 t ADT: 10

WILEYS RD

Good

Over: W OTTER CREEK

086082401, Linn, IA

Built 2001 Load: 57.9 t ADT: 49

RING RD

Good

Over: E BLUE CREEK

086082803, Linn, IA

Built 2001 Load: 57.9 t ADT: 29

RING RD

Good

Over: EAST BLUE CREEK

086082808, Linn, IA

Built 2003 Load: 57.9 t ADT: 29

FEE RD

Good

Over: E BLUE CREEK

086083307, Linn, IA

Built 2007 Load: 57.9 t ADT: 70

GRUBBS CR RD

Good

Over: CRUBB CREEK

086083405, Linn, IA

Built 1997 Load: 57.9 t ADT: 70

UP.BOULDER RD

Good

Over: BISON CREEK

086051803, Linn, IA

Built 1995 Load: 57.9 t ADT: 29

UPPER BOULDER R

Good

Over: SILVER CREEK

086051401, Linn, IA

Built 1998 Load: 57.9 t ADT: 11

MORGAN BR RD

Good

Over: MORGAN CREEK

083082802, Linn, IA

Built 2000 Load: 57.9 t ADT: 34

ALDERMAN RD

Good

Over: LITTLE BIG CREEK

084051502, Linn, IA

Built 2000 Load: 57.9 t ADT: 59

PARIS RD

Good

Over: EAST OTTER CREEK

086072701, Linn, IA

Built 2000 Load: 57.9 t ADT: 216

NORTH MARION RD

Good

Over: DRY CREEK

085060702, Linn, IA

Built 2001 Load: 57.9 t ADT: 44

Showing 16,251-16,300 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.