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 - 180TH ST

Fair

Over: SMALL STREAM

089041305, Delaware, IA

Built 1976 Load: 22.0 t ADT: 44

LOC 160 ST

Fair

Over: SMALL STREAM

089060501, Delaware, IA

Built 1980 Load: 22.0 t ADT: 29

210TH AVE

Fair

Over: SMALL STREAM

090052404, Delaware, IA

Built 1978 Load: 22.0 t ADT: 44

LOCAL

Fair

Over: WHITEWATER CREEK

088E11802, Dubuque, IA

Built 1979 Load: 22.0 t ADT: 25

FM

Fair

Over: GRANGER CREEK

000000000, Dubuque, IA

Built 2009 Load: 22.0 t ADT: 25

LOCAL

Fair

Over: SMALL

090012303, Dubuque, IA

Built 1983 Load: 22.0 t ADT: 79

LOCAL

Fair

Over: CREEK

084E50604, Jackson, IA

Built 1981 Load: 22.0 t ADT: 60

LOCAL

Fair

Over: SUGAR CREEK

084E53004, Jackson, IA

Built 1957 Load: 22.0 t ADT: 71

15TH AVE.

Fair

Over: MINERAL CREEK

085012504, Jones, IA

Built 1950 Load: 22.0 t ADT: 34

180TH ST

Fair

Over: SMALL STREAM

085040701, Jones, IA

Built 1994 Load: 22.0 t ADT: 20

FM

Fair

Over: BARLENE CREEK

066063606, Lee, IA

Built 1975 Load: 22.0 t ADT: 90

FROZEN HILL RD

Fair

Over: BUFFALO CREEK

085051302, Linn, IA

Built 1951 Load: 22.0 t ADT: 49

LOCAL

Fair

Over: TRIB BUFFALO CREEK

086060301, Linn, IA

Built 1994 Load: 22.0 t ADT: 88

LOCAL RD

Fair

Over: DRAINAGE

076261403, Madison, IA

Built 1946 Load: 22.0 t ADT: 20

LOCAL

Fair

Over: BR BURNETT CR

085172901, Marshall, IA

Built 1957 Load: 22.0 t ADT: 11

MONROE AVE

Fair

Over: DEEP CREEK

094422902, O'Brien, IA

Built 2007 Load: 22.0 t ADT: 11

LOCAL

Fair

Over: DD 175

095330801, Palo Alto, IA

Built 1956 Load: 22.0 t ADT: 11

240TH ST

Fair

Over: DRY BRANCH

091441601, Plymouth, IA

Built 1900 Load: 22.0 t ADT: 71

350TH STREET

Fair

Over: SILVER CREEK

076412402, Pottawattamie, IA

Built 1996 Load: 22.0 t ADT: 5

LOCAL

Fair

Over: SMALL STREAM

078390503, Shelby, IA

Built 1957 Load: 22.0 t ADT: 41

CEDAR RD

Fair

Over: DRAINAGE

079403302, Shelby, IA

Built 1954 Load: 22.0 t ADT: 26

LOCAL

Fair

Over: WEST BRANCH

094452001, Sioux, IA

Built 1938 Load: 22.0 t ADT: 26

S60 235TH ST

Fair

Over: WALNUT CREEK

069202610, Wayne, IA

Built 1958 Load: 22.0 t ADT: 980

LOCAL ROAD

Fair

Over: CREEK

098101201, Winneshiek, IA

Built 1953 Load: 22.0 t ADT: 44

ORANGE AVENUE

Fair

Over: BROWN BRANCH

072331502, Adams, IA

Built 1967 Load: 22.1 t ADT: 45

LOCAL

Fair

Over: BR MUD CK

084111502, Benton, IA

Built 1972 Load: 22.1 t ADT: 26

LOCAL

Fair

Over: SPRING CK

086111502, Benton, IA

Built 1974 Load: 22.1 t ADT: 40

UNIVERSITY AVE

Fair

Over: BLACK HAWK CREEK

0.4 MI. W of Jct. U.S. 63, Black Hawk, IA

Built 1955 Load: 22.1 t ADT: 3,388

FM MARQUIS RD

Fair

Over: STREAM

090130201, Black Hawk, IA

Built 1961 Load: 22.1 t ADT: 49

LOCAL

Fair

Over: TRIB DES MOINES RIVER

083261904, Boone, IA

Built 1950 Load: 22.1 t ADT: 30

LOCAL/VICTORIA

Fair

Over: THREE MILE CREEK

074362303, Cass, IA

Built 1976 Load: 22.1 t ADT: 41

LOCAL

Fair

Over: STREAM

079011201, Cedar, IA

Built 1975 Load: 22.1 t ADT: 81

FM

Fair

Over: PLUM CREEK

082012304, Cedar, IA

Built 1957 Load: 22.1 t ADT: 740

LOCAL- W AVE

Fair

Over: LITTLE MAPLE RIVER

090393502, Cherokee, IA

Built 1963 Load: 22.1 t ADT: 40

LOCAL

Fair

Over: PLUM CREEK

095121009, Chickasaw, IA

Built 2004 Load: 22.1 t ADT: 51

LOCAL

Fair

Over: LITTLE TURKEY RIVER

097112002, Chickasaw, IA

Built 2002 Load: 22.1 t ADT: 41

FM

Fair

Over: SMALL STREAM

084410201, Crawford, IA

Built 1940 Load: 22.1 t ADT: 89

FM

Fair

Over: YELLOW SPRING CREEK

071022204, Des Moines, IA

Built 1951 Load: 22.1 t ADT: 100

LOCAL

Fair

Over: CREEK

098351401, Dickinson, IA

Built 1971 Load: 22.1 t ADT: 102

LOCAL

Fair

Over: MUDDY CREEK

098352204, Dickinson, IA

Built 1971 Load: 22.1 t ADT: 61

FM

Fair

Over: W BR LITTLE SIOUX RIVER

100382002, Dickinson, IA

Built 1973 Load: 22.1 t ADT: 20

LOCAL

Fair

Over: CREEK

095182501, Floyd, IA

Built 1980 Load: 22.1 t ADT: 29

FM (50TH ST)

Fair

Over: N BEAVER CREEK

090192201, Franklin, IA

Built 1972 Load: 22.1 t ADT: 34

LOCAL RAVEN AVE

Fair

Over: BEAVER CREEK

090202502, Franklin, IA

Built 1971 Load: 22.1 t ADT: 26

LOCAL 30TH ST

Fair

Over: DRAINAGE DITCH NO 13

090203501, Franklin, IA

Built 1970 Load: 22.1 t ADT: 59

FM

Fair

Over: BLACKHAWK CREEK ,BRANCH

087160102, Grundy, IA

Built 1966 Load: 22.1 t ADT: 579

IA 175

Fair

Over: STREAM

0.1 MILE W OF W JCT IA 14, Grundy, IA

Built 1962 Load: 22.1 t ADT: 1,090

820 180TH ST

Fair

Over: BR. BOONE RIVER #8

095252901, Hancock, IA

Built 1981 Load: 22.1 t ADT: 21

2830 SAGE AVE

Fair

Over: IA RIVER EAST BRANCH

097233102, Hancock, IA

Built 1985 Load: 22.1 t ADT: 15

FM

Fair

Over: CREEK

088402604, Ida, IA

Built 1962 Load: 22.1 t ADT: 50

Showing 3,151-3,200 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.