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: HAWK RUN CREEK

075211201, Marion, IA

Built 1988 Load: 32.2 t ADT: 62

SB US 75

Fair

Over: DRY CREEK

1.9 mi. N of jct. SR C60, Plymouth, IA

Built 1948 Load: 32.2 t ADT: 7,000

US 59

Fair

Over: STREAM

0.9 MI. S OF S JCT SR G30, Pottawattamie, IA

Built 1952 Load: 32.2 t ADT: 1,780

IA 471

Fair

Over: BOYER RIVER

3.5 mi. N of Jct IA 175, Sac, IA

Built 1984 Load: 32.2 t ADT: 1,070

SB I-35

Fair

Over: LONG DICK CREEK

0.5 MILES N OF SR E18, Story, IA

Built 1967 Load: 32.2 t ADT: 14,850

FM

Fair

Over: WOLF CREEK

073292403, Union, IA

Built 2001 Load: 32.2 t ADT: 100

LOCAL

Fair

Over: STREAM

067201902, Wayne, IA

Built 1990 Load: 32.2 t ADT: 11

ASHLEY RD

Fair

Over: TRIB TO CEDAR RIVER

87-11-07-03-10, Black Hawk, IA

Built 1983 Load: 32.3 t ADT: 44

IA 3

Fair

Over: DRAINAGE DITCH

0.2 mi. W of Jct. US 218, Bremer, IA

Built 1967 Load: 32.3 t ADT: 6,100

LOCAL SDB

Fair

Over: DRAINAGE

085351502, Carroll, IA

Built 1940 Load: 32.3 t ADT: 45

I-80

Fair

Over: LITTLE ELKHORN CREEK

2.9 mi. E of E Jct. IA 38, Cedar, IA

Built 1959 Load: 32.3 t ADT: 35,400

S25 GROUSE AVE

Fair

Over: BEAVER DAM CREEK

095210704, Cerro Gordo, IA

Built 1986 Load: 32.3 t ADT: 815

JONQUIL AVE

Fair

Over: WEST FORK BEAVER DAM CR

094211502, Cerro Gordo, IA

Built 1981 Load: 32.3 t ADT: 147

KILLDEER

Fair

Over: CALMUS CREEK

097212602, Cerro Gordo, IA

Built 1981 Load: 32.3 t ADT: 628

420TH ST

Fair

Over: WILLOW CREEK

095382201, Clay, IA

Built 1978 Load: 32.3 t ADT: 11

290TH AVE

Fair

Over: STREAM

096352002, Clay, IA

Built 1994 Load: 32.3 t ADT: 103

380TH ST

Fair

Over: PRAIRIE CK

096363301, Clay, IA

Built 1977 Load: 32.3 t ADT: 30

330TH ST

Fair

Over: STREAM

096380201, Clay, IA

Built 1900 Load: 32.3 t ADT: 123

FM 350TH ST

Fair

Over: DRAINAGE

096381701, Clay, IA

Built 1972 Load: 32.3 t ADT: 908

FM 100TH AVE

Fair

Over: STREAM

096381802, Clay, IA

Built 1972 Load: 32.3 t ADT: 529

352ND ST

Fair

Over: STREAM

091021003, Clayton, IA

Built 1998 Load: 32.3 t ADT: 41

160TH ST

Fair

Over: STREAM

094060403, Clayton, IA

Built 1981 Load: 32.3 t ADT: 11

FM

Fair

Over: SOAP CREEK

070131006, Davis, IA

Built 1987 Load: 32.3 t ADT: 380

GRAIN RD.

Fair

Over: UNAMED CR

093082406, Fayette, IA

Built 1998 Load: 32.3 t ADT: 20

I-35

Fair

Over: DRAINAGE DITCH

1.1 MI. S OF SR C13, Franklin, IA

Built 1972 Load: 32.3 t ADT: 16,900

BLUFF ROAD

Fair

Over: STREAM

067420503, Fremont, IA

Built 1960 Load: 32.3 t ADT: 249

FM

Fair

Over: TRIBUTARY TO TROUBLESOME

079330502, Guthrie, IA

Built 1951 Load: 32.3 t ADT: 199

SW 480TH ST

Fair

Over: BR DIRTY FACE CR

078071101, Johnson, IA

Built 1920 Load: 32.3 t ADT: 61

CHAMBERS AVE

Fair

Over: CLEAR CREEK

080082804, Johnson, IA

Built 1977 Load: 32.3 t ADT: 170

LINN-JOHNSON RD

Fair

Over: KNAPP CREEK

081080601, Johnson, IA

Built 1984 Load: 32.3 t ADT: 46

IA 136

Fair

Over: STREAM

3.5 mi. N of Jct. SR E17, Jones, IA

Built 1940 Load: 32.3 t ADT: 770

GRANT ST

Fair

Over: DRAINAGE

000000000, Linn, IA

Built 1977 Load: 32.3 t ADT: 2,455

CHAIN BRIDGE ROAD

Fair

Over: LONE TREE CREEK

000000000, Linn, IA

Built 1984 Load: 32.3 t ADT: 171

US 61

Fair

Over: MUSKRAT LAKE

4.6 mi. S of S Jct. IA 92, Louisa, IA

Built 1985 Load: 32.3 t ADT: 4,950

FM

Fair

Over: CEDAR CREEK

074151405, Mahaska, IA

Built 1957 Load: 32.3 t ADT: 120

FM

Fair

Over: SMALL STREAM

083170808, Marshall, IA

Built 1984 Load: 32.3 t ADT: 157

FM

Fair

Over: NISHNABOTNA TRIB

071380901, Montgomery, IA

Built 1959 Load: 32.3 t ADT: 72

FM

Fair

Over: CREEK

098400502, Osceola, IA

Built 1966 Load: 32.3 t ADT: 71

LOCAL

Fair

Over: STREAM

098402702, Osceola, IA

Built 1976 Load: 32.3 t ADT: 41

FM

Fair

Over: WAGNER CR

098420203, Osceola, IA

Built 1974 Load: 32.3 t ADT: 71

FM

Fair

Over: RAT CREEK

098420401, Osceola, IA

Built 1990 Load: 32.3 t ADT: 578

FM

Fair

Over: KAPPES CREEK

098421204, Osceola, IA

Built 1958 Load: 32.3 t ADT: 439

FM

Fair

Over: DRY RUN

098421204, Osceola, IA

Built 1924 Load: 32.3 t ADT: 439

FM

Fair

Over: RUSH LAKE OUTLET

099401401, Osceola, IA

Built 1984 Load: 32.3 t ADT: 828

FM

Fair

Over: CREEK

099402402, Osceola, IA

Built 1967 Load: 32.3 t ADT: 569

FM

Fair

Over: POLLY CREEK

099410604, Osceola, IA

Built 1955 Load: 32.3 t ADT: 718

FM

Fair

Over: DRAINAGE DITCH

099412102, Osceola, IA

Built 1959 Load: 32.3 t ADT: 110

FM

Fair

Over: DAWSON CREEK

099412902, Osceola, IA

Built 1992 Load: 32.3 t ADT: 459

LOCAL

Fair

Over: DRY RUN

099422701, Osceola, IA

Built 1972 Load: 32.3 t ADT: 35

US 71

Fair

Over: DRAINAGE DITCH

1.2 mi. N of Jct. SR J-53, Page, IA

Built 1973 Load: 32.3 t ADT: 3,000

Showing 6,201-6,250 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.