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

LOCAL

Fair

Over: PLATTE RIVER

071312301, Union, IA

Built 1986 Load: 36.5 t ADT: 72

GROVE AVENUE

Fair

Over: EAST NODAWAY RIVER

071340734, Adams, IA

Built 1996 Load: 36.6 t ADT: 50

FIG AVENUE

Fair

Over: EAST NODAWAY RIVER

071351206, Adams, IA

Built 1995 Load: 36.6 t ADT: 5

MOCKINGBIRD AVE

Fair

Over: CREEK

081341802, Audubon, IA

Built 1993 Load: 36.6 t ADT: 11

LOCAL

Fair

Over: CREEK

094122403, Chickasaw, IA

Built 2007 Load: 36.6 t ADT: 26

LOCAL

Fair

Over: DRY RUN

095110105, Chickasaw, IA

Built 1991 Load: 36.6 t ADT: 30

LOCAL

Fair

Over: PLUM CREEK

095120304, Chickasaw, IA

Built 1994 Load: 36.6 t ADT: 104

155TH ST

Fair

Over: SMALL STREAM

090053105, Delaware, IA

Built 1983 Load: 36.6 t ADT: 49

FM

Fair

Over: STREAM

076111201, Keokuk, IA

Built 1950 Load: 36.6 t ADT: 70

IA 9

Fair

Over: ROCK RIVER

0.5 mi. E of E Jct. US 75, Lyon, IA

Built 1974 Load: 36.6 t ADT: 3,920

FM

Fair

Over: W NODAWAY RIVER

072362801, Montgomery, IA

Built 1987 Load: 36.6 t ADT: 338

LOCAL

Fair

Over: D.D. #51

079241461, Polk, IA

Built 1991 Load: 36.6 t ADT: 180

FM

Fair

Over: NORTH SKUNK RIVER

078162003, Poweshiek, IA

Built 1997 Load: 36.6 t ADT: 40

1ST AVE

Fair

Over: BR MUD CREEK

079E10702, Scott, IA

Built 1988 Load: 36.6 t ADT: 71

R70/580TH AVE

Fair

Over: SKUNK RIVER

082230904, Story, IA

Built 1989 Load: 36.6 t ADT: 818

SB IA 5

Fair

Over: NORTH RIVER

0.9 MI. S OF JCT US 65, Warren, IA

Built 1996 Load: 36.6 t ADT: 8,250

NB US 218

Fair

Over: CP RR

0.2 MI. N OF JCT. IA 92, Washington, IA

Built 1996 Load: 36.6 t ADT: 5,500

NB US 218

Fair

Over: N FK LONG CREEK

1.0 MI. S OF JCT. IA 92, Washington, IA

Built 1997 Load: 36.6 t ADT: 5,400

LOCAL

Fair

Over: GOODWATER

070200401, Wayne, IA

Built 1997 Load: 36.6 t ADT: 34

LOCAL

Fair

Over: BEAVER CREEK

098232601, Winnebago, IA

Built 1991 Load: 36.6 t ADT: 30

US 30 EB

Fair

Over: MUD CREEK

0.9 mi. W of Jct. SR W14, Benton, IA

Built 1998 Load: 36.7 t ADT: 4,750

FM

Fair

Over: DRAINAGE DITCH

088182903, Grundy, IA

Built 1955 Load: 36.7 t ADT: 491

US 30

Fair

Over: MISSOURI RIVER

AT NEBRASKA STATE LINE, Harrison, IA

Built 1991 Load: 36.7 t ADT: 4,410

I-80

Fair

Over: ELK CREEK

4.2 MILES W OF JCT IA 224, Jasper, IA

Built 1961 Load: 36.7 t ADT: 30,000

ARTESIAN RD

Fair

Over: INDIAN CREEK

084062000, Linn, IA

Built 1999 Load: 36.7 t ADT: 60

IA 37

Fair

Over: NORWAY CREEK

2.6 mi. E of IA 183, Monona, IA

Built 1959 Load: 36.7 t ADT: 620

FM

Fair

Over: TRIB OF W NODAWAY

072361602, Montgomery, IA

Built 1995 Load: 36.7 t ADT: 50

LOCAL

Fair

Over: DD #22

094341902, Palo Alto, IA

Built 1982 Load: 36.7 t ADT: 11

NB I-29

Fair

Over: CC&P RR

2.1 MI. N OF JCT. US 6, Pottawattamie, IA

Built 1968 Load: 36.7 t ADT: 5,400

US 63 NB

Fair

Over: SUGAR CREEK

1.7 mi. N of N Jct. US 34, Wapello, IA

Built 2007 Load: 36.7 t ADT: 3,400

US 63 SB

Fair

Over: SUGAR CREEK

1.7 mi. N of N Jct. US 34, Wapello, IA

Built 2007 Load: 36.7 t ADT: 3,400

160TH ST

Fair

Over: DRAINAGE DITCH

098122701, Howard, IA

Built 1988 Load: 36.8 t ADT: 21

US 59

Fair

Over: SILVER CREEK

2.1 mi. N of SR D15, Ida, IA

Built 1972 Load: 36.8 t ADT: 2,200

S 52ND AVE E

Fair

Over: PRAIRIE CREEK

079182201, Jasper, IA

Built 1949 Load: 36.8 t ADT: 16

FM

Fair

Over: DRAINAGE

077140101, Mahaska, IA

Built 1990 Load: 36.8 t ADT: 60

S 45

Fair

Over: WHITE BREAST CREEK

075212606, Marion, IA

Built 1979 Load: 36.8 t ADT: 1,810

X 54

Fair

Over: SUGAR CREEK

At the jct. of SR X54, Muscatine, IA

Built 1971 Load: 36.8 t ADT: 10

IA 415

Fair

Over: SAYLORVILLE RESERVOIR

West of Polk City, Polk, IA

Built 1973 Load: 36.8 t ADT: 10,100

FM

Fair

Over: BOYER RIVER

086371403, Sac, IA

Built 1950 Load: 36.8 t ADT: 489

IA 44

Fair

Over: WEST NISHNABOTNA RIVER

5.8 E OF JCT. U.S. 59, Shelby, IA

Built 1984 Load: 36.8 t ADT: 2,690

SB US 63

Fair

Over: COMSTOCK CREEK

0.6 MI. S of SR T67, Wapello, IA

Built 1988 Load: 36.8 t ADT: 4,600

US 20 RAMP

Fair

Over: ABAND RR

0.1 mi. E of SR D25, Woodbury, IA

Built 1978 Load: 36.8 t ADT: 1,200

FM

Fair

Over: BUCKEYE CREEK

082122405, Benton, IA

Built 1960 Load: 36.9 t ADT: 850

FM

Fair

Over: MUD CREEK

085102205, Benton, IA

Built 1992 Load: 36.9 t ADT: 1,532

FM

Fair

Over: BEAR CREEK

086100206, Benton, IA

Built 1991 Load: 36.9 t ADT: 658

FM

Fair

Over: BUCK CREEK

090102006, Buchanan, IA

Built 1972 Load: 36.9 t ADT: 1,277

NB I-35

Fair

Over: OVER IMRL RR

0.2 MI. S OF JCT. 18, Cerro Gordo, IA

Built 1970 Load: 36.9 t ADT: 10,800

FROELICH RD

Fair

Over: STREAM

095043303, Clayton, IA

Built 1904 Load: 36.9 t ADT: 154

FM

Fair

Over: RACCOON RIVER OVERFLOW

078263005, Dallas, IA

Built 1973 Load: 36.9 t ADT: 1,942

FM

Fair

Over: CALEB CREEK

067241404, Decatur, IA

Built 1977 Load: 36.9 t ADT: 379

Showing 7,801-7,850 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.