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

Fair

Over: PAINTER CREEK

067051905, Lee, IA

Built 1972 Load: 37.6 t ADT: 1,400

MILLER ROAD

Fair

Over: TOWER CREEK

000000000, Linn, IA

Built 1996 Load: 37.6 t ADT: 2,740

IA 92

Fair

Over: MONKEY RUN CREEK

3.0 mi. W of jct. IA 70, Louisa, IA

Built 1984 Load: 37.6 t ADT: 4,160

LOCAL

Fair

Over: BR OF CHARITON RIVER

071211301, Lucas, IA

Built 1951 Load: 37.6 t ADT: 41

FM

Fair

Over: BR OF STONY CREEK

073220802, Lucas, IA

Built 1947 Load: 37.6 t ADT: 35

FM

Fair

Over: THUNDER CREEK

077182608, Marion, IA

Built 1987 Load: 37.6 t ADT: 400

BARRUS RD

Fair

Over: SNAKE CREEK

073420807, Mills, IA

Built 1978 Load: 37.6 t ADT: 358

E 2ND ST

Fair

Over: MAD CREEK

3.4 MI. E OF W JCT. US 61, Muscatine, IA

Built 1963 Load: 37.6 t ADT: 8,700

IA 22

Fair

Over: PIKE RUN CREEK

1.2 mi. E of jct. IA 70, Muscatine, IA

Built 1987 Load: 37.6 t ADT: 3,650

IA 3

Fair

Over: STREAM

1.0 mi. W of S.R. K42, Plymouth, IA

Built 1954 Load: 37.6 t ADT: 1,420

LOCAL ROAD

Fair

Over: WOLFE CREEK

081253605, Polk, IA

Built 1993 Load: 37.6 t ADT: 349

MAGNOLIA ROAD

Fair

Over: WALNUT CREEK

076382201, Pottawattamie, IA

Built 1972 Load: 37.6 t ADT: 50

ALLENS GROVE RD

Fair

Over: MUD CREEK

080E22903, Scott, IA

Built 1987 Load: 37.6 t ADT: 550

US 59

Fair

Over: WILLOW CREEK

3.4 mi. N of jct. IA 37, Shelby, IA

Built 1970 Load: 37.6 t ADT: 2,780

LOCAL

Fair

Over: CREEK

072300301, Union, IA

Built 1952 Load: 37.6 t ADT: 11

LOCAL

Fair

Over: CHEQUEST CREEK

069102710, Van Buren, IA

Built 2005 Load: 37.6 t ADT: 140

IA 92

Fair

Over: SOUTH LONG CREEK

4.6 MI. W OF JCT. US 218, Washington, IA

Built 1967 Load: 37.6 t ADT: 5,800

NB IA 376

Fair

Over: DRY CREEK

0.1 mi. N of Jct. SR D12, Woodbury, IA

Built 1931 Load: 37.6 t ADT: 3,750

LOCAL (LWC)

Fair

Over: BEAR CREEK

086102202, Benton, IA

Built 1980 Load: 37.7 t ADT: 70

LOCAL

Fair

Over: WEST FORK CEDAR RIVER

091180106, Butler, IA

Built 1962 Load: 37.7 t ADT: 47

US 218

Fair

Over: CEDAR RIVER

0.2 mi. S of S.R. B33, Floyd, IA

Built 1979 Load: 37.7 t ADT: 2,910

FM

Fair

Over: TAFT CREEK

099433302, Lyon, IA

Built 1967 Load: 37.7 t ADT: 100

FM

Fair

Over: MIDDLE CREEK

076150803, Mahaska, IA

Built 1990 Load: 37.7 t ADT: 370

LOCAL

Fair

Over: SOAP CREEK

071172404, Monroe, IA

Built 1989 Load: 37.7 t ADT: 30

FM

Fair

Over: MILL CREEK

094411501, O'Brien, IA

Built 1970 Load: 37.7 t ADT: 71

COUNTY RD

Fair

Over: WILLOW CREEK

095430310, Sioux, IA

Built 1991 Load: 37.7 t ADT: 1,347

FM

Fair

Over: SOUTH RIVER

075240304, Warren, IA

Built 1990 Load: 37.7 t ADT: 780

LOCAL

Fair

Over: JACKSON CR

069211203, Wayne, IA

Built 1988 Load: 37.7 t ADT: 11

LOCAL

Fair

Over: W. BR. IOWA RIVER

093240202, Wright, IA

Built 1990 Load: 37.7 t ADT: 26

FM

Fair

Over: NINE MILE RUN

075303104, Adair, IA

Built 1989 Load: 37.8 t ADT: 1,374

LOCAL

Fair

Over: BEAR CREEK

087192402, Hardin, IA

Built 1979 Load: 37.8 t ADT: 35

WINSLOW RD

Fair

Over: TRIB INDIAN CREEK

084061900, Linn, IA

Built 1999 Load: 37.8 t ADT: 1,129

LOCAL ROAD

Fair

Over: CREEK

098070704, Winneshiek, IA

Built 2003 Load: 37.8 t ADT: 78

LOCAL

Fair

Over: SMALL

068191602, Appanoose, IA

Built 1900 Load: 37.9 t ADT: 26

LOCAL

Fair

Over: COOPER CREEK

069182503, Appanoose, IA

Built 1997 Load: 37.9 t ADT: 680

LOCAL

Fair

Over: BEAVER CREEK

084282102, Boone, IA

Built 1900 Load: 37.9 t ADT: 5

LOCAL

Fair

Over: CREEK

096132702, Chickasaw, IA

Built 1993 Load: 37.9 t ADT: 104

LOCAL

Fair

Over: CREEK

096142201, Chickasaw, IA

Built 1995 Load: 37.9 t ADT: 35

LOCAL

Fair

Over: CREEK

097132201, Chickasaw, IA

Built 1991 Load: 37.9 t ADT: 20

330TH ST

Fair

Over: SPRING CREEK

092063605, Clayton, IA

Built 2012 Load: 37.9 t ADT: 35

NB US 61

Fair

Over: SILVER CREEK

0.9 MI. N OF N JCT US 30, Clinton, IA

Built 1974 Load: 37.9 t ADT: 6,350

LOCAL 120 AVE

Fair

Over: SMALL STREAM

088062802, Delaware, IA

Built 1982 Load: 37.9 t ADT: 5

LOC 155TH ST

Fair

Over: SMALL STREAM

090063605, Delaware, IA

Built 1982 Load: 37.9 t ADT: 49

FM

Fair

Over: SMALL STREAM

069032905, Des Moines, IA

Built 1951 Load: 37.9 t ADT: 150

IA 3 & 150

Fair

Over: STREAM

.25 MI. S OF N JCT IA 150, Fayette, IA

Built 1978 Load: 37.9 t ADT: 2,580

FM ELY RD

Fair

Over: LINGLE CREEK

081060904, Johnson, IA

Built 1955 Load: 37.9 t ADT: 3,930

EB I-235

Fair

Over: WALNUT CREEK

3.4 MI. E OF W JCT. 35/80, Polk, IA

Built 1968 Load: 37.9 t ADT: 58,050

NE 80TH ST

Fair

Over: MUD CREEK

079220804, Polk, IA

Built 1990 Load: 37.9 t ADT: 528

US 6

Fair

Over: MIDDLE SILVER CREEK

2.0 mi. E of W jct SR L55, Pottawattamie, IA

Built 1998 Load: 37.9 t ADT: 2,770

6TH STREET

Fair

Over: INDIAN CREEK

6th St over Indian Creek, Pottawattamie, IA

Built 1983 Load: 37.9 t ADT: 5,275

Showing 7,951-8,000 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.