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

76TH AVE SW

Good

Over: TISSLE HOLLOW CREEK

Linn # 1182, Linn, IA

Built 2010 Load: 57.9 t ADT: 137

LOCAL

Good

Over: WEST FORK MEDICINE

067220504, Wayne, IA

Built 1998 Load: 57.9 t ADT: 15

LOCAL

Good

Over: BEAR CREEK

100063203, Allamakee, IA

Built 2000 Load: 58.0 t ADT: 20

IRIS AVE

Good

Over: BLOODY RUN

095042404, Clayton, IA

Built 1996 Load: 58.0 t ADT: 59

445TH AVENYE

Good

Over: ELK RIVER

083E61106, Clinton, IA

Built 2005 Load: 58.0 t ADT: 62

315TH ST

Good

Over: KEG CREEK

078412301, Harrison, IA

Built 1999 Load: 58.0 t ADT: 20

SPOKANE AVE

Good

Over: MILL CREEK

081412104, Harrison, IA

Built 2003 Load: 58.0 t ADT: 45

383RD AVE

Good

Over: SUGAR CREEK

084E42504, Jackson, IA

Built 2019 Load: 58.0 t ADT: 29

FM

Good

Over: FARMERS CREEK

085E30610, Jackson, IA

Built 1993 Load: 58.0 t ADT: 35

MIDWAY RD

Good

Over: E OTTER CR

084070705, Linn, IA

Built 2005 Load: 58.0 t ADT: 255

US 30

Good

Over: SALT CREEK

0.8 mi. W of Jct. IA 21, Tama, IA

Built 1989 Load: 58.0 t ADT: 4,510

LINTON DR

Good

Over: BRANCH YELLOW RIVER

096041603, Allamakee, IA

Built 2005 Load: 58.1 t ADT: 100

FM F-58

Good

Over: CROOKED CREEK

078342702, Audubon, IA

Built 2003 Load: 58.1 t ADT: 278

FM

Good

Over: S FK MAQUOKETA RIVER

090070903, Buchanan, IA

Built 1990 Load: 58.1 t ADT: 44

CRYSTAL RD

Good

Over: STREAM

092062507, Clayton, IA

Built 1988 Load: 58.1 t ADT: 88

120TH ST.

Good

Over: DEEP CREEK

083E51701, Clinton, IA

Built 2003 Load: 58.1 t ADT: 104

E18/130TH ST

Good

Over: SKUNK RIVER

085231901, Story, IA

Built 2000 Load: 58.1 t ADT: 4,209

ALBURNETT RD

Good

Over: DRY CREEK

085073608, Linn, IA

Built 1996 Load: 58.3 t ADT: 1,895

QUAIL RUN

Good

Over: STREAM

069220401, Wayne, IA

Built 2016 Load: 58.3 t ADT: 26

LOCAL

Good

Over: SPRING CREEK

086111501, Benton, IA

Built 1996 Load: 58.4 t ADT: 26

LOCAL

Good

Over: BUCK CREEK

089251405, Hamilton, IA

Built 1994 Load: 58.4 t ADT: 71

208 AVE

Good

Over: DEEP CREEK

083E23504, Clinton, IA

Built 2000 Load: 58.6 t ADT: 11

390TH AVE.

Good

Over: STREAM

082E51202, Clinton, IA

Built 1959 Load: 58.8 t ADT: 51

FM

Good

Over: MINERVA CREEK

086220902, Hardin, IA

Built 1998 Load: 58.8 t ADT: 236

US 67

Good

Over: DUCK CREEK

7.0 MI. S OF JCT. I-80, Scott, IA

Built 1996 Load: 58.8 t ADT: 15,500

IA 37

Good

Over: JORDAN CREEK

6.3 mi. E of IA 175, Monona, IA

Built 1979 Load: 58.9 t ADT: 780

510TH AVE

Good

Over: MOON CREEK

078152201, Poweshiek, IA

Built 2022 Load: 58.9 t ADT: 5

MLK JR. DR.

Good

Over: SMALL STREAM

CITY CULVERT NO. 57C, Black Hawk, IA

Built 2000 Load: 59.0 t ADT: 4,875

RUTLEDGE ST

Good

Over: TRACY CREEK

074200901, Marion, IA

Built 2012 Load: 59.0 t ADT: 47

FM

Good

Over: MILL CREEK

094413301, O'Brien, IA

Built 2008 Load: 59.0 t ADT: 159

E 84TH ST S

Good

Over: PRAIRIE CREEK

079182204, Jasper, IA

Built 2016 Load: 59.1 t ADT: 41

SB US 218

Good

Over: OLD MAN CREEK OVERFLOW

0.6 MI. N of Jct. SR F62, Johnson, IA

Built 1983 Load: 59.1 t ADT: 10,250

WILLOW CR.RD.

Good

Over: WILLOW CREEK

082051604, Linn, IA

Built 1996 Load: 59.1 t ADT: 39

AUSTIN RD

Good

Over: E INDIAN CREEK

084060401, Linn, IA

Built 1994 Load: 59.1 t ADT: 90

DEPOT RD

Good

Over: UNNAMED CREEK

093072105, Fayette, IA

Built 2021 Load: 59.3 t ADT: 20

LOCAL

Good

Over: UPPER IOWA RIVER

098081304, Winneshiek, IA

Built 1988 Load: 59.7 t ADT: 442

VETERANS PARKWAY

Good

Over: TRIB TO CHERRY CREEK

0.5 MI. E. of Vintage Ave, Madison, IA

Built 2018 Load: 59.9 t ADT: 11

FM-HEMLOCK AVE

Good

Over: STREAM

000000000, Pottawattamie, IA

Built 2010 Load: 60.0 t ADT: 34

OLYMPIC RD

Good

Over: SMALL

071030709, Des Moines, IA

Built 2005 Load: 60.2 t ADT: 62

E GRESHAM RD

Good

Over: TRIB QUARTER SECTION RUN

90-13-12-01-10, Black Hawk, IA

Built 1924 Load: 60.3 t ADT: 69

US 30

Good

Over: DRAINAGE

1.4 mi. E US30/IA1 INTCHG, Linn, IA

Built 2018 Load: 60.3 t ADT: 5,400

210TH ST.

Good

Over: UNAMED CR

094082903, Fayette, IA

Built 1988 Load: 60.4 t ADT: 304

FM

Good

Over: LITTLE OCHEYEDAN RIVER

099411301, Osceola, IA

Built 1977 Load: 60.4 t ADT: 818

FM-400TH STREET

Good

Over: SLOCUM CREEK

075401102, Pottawattamie, IA

Built 1979 Load: 60.4 t ADT: 79

FM-310TH STREET

Good

Over: LITTLE SILVER CREEK

075410502, Pottawattamie, IA

Built 1979 Load: 60.4 t ADT: 89

FM-MAHOGANY RD

Good

Over: SIMON RUN

076430705, Pottawattamie, IA

Built 1976 Load: 60.4 t ADT: 199

IA 330 NB

Good

Over: NORTH TIMBER CREEK

2.7 MILES S OF JCT US 30, Marshall, IA

Built 2002 Load: 60.5 t ADT: 4,500

INDIAN CREEK ST

Good

Over: TRIB TO INDIAN CREEK

075370502, Cass, IA

Built 2021 Load: 60.6 t ADT: 71

485TH ST

Good

Over: STREAM

069161303, Appanoose, IA

Built 2012 Load: 60.8 t ADT: 30

LOCAL

Good

Over: STREAM

068210401, Wayne, IA

Built 1995 Load: 60.8 t ADT: 20

Showing 16,301-16,350 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.