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: CANOE CREEK BRANCH

099080205, Winneshiek, IA

Built 1971 Load: 18.1 t ADT: 265

POLE LINE RD

Fair

Over: SMALL STREAM

099092904, Winneshiek, IA

Built 1950 Load: 18.1 t ADT: 344

LOCAL ROAD

Fair

Over: CREEK

099101703, Winneshiek, IA

Built 1968 Load: 18.1 t ADT: 40

LOCAL ROAD

Fair

Over: DRAINAGE

100071003, Winneshiek, IA

Built 1969 Load: 18.1 t ADT: 70

FM

Fair

Over: SILVER CREEK

100092601, Winneshiek, IA

Built 1973 Load: 18.1 t ADT: 560

FM

Fair

Over: CREEK

100092803, Winneshiek, IA

Built 1962 Load: 18.1 t ADT: 560

FM

Fair

Over: PINE CREEK

100092804, Winneshiek, IA

Built 1962 Load: 18.1 t ADT: 120

FM

Fair

Over: PINE CREEK

100092901, Winneshiek, IA

Built 1962 Load: 18.1 t ADT: 560

FM

Fair

Over: CREEK

100101501, Winneshiek, IA

Built 1961 Load: 18.1 t ADT: 120

LOCAL RD

Fair

Over: SHANGHAR CREEK

074322703, Adair, IA

Built 1960 Load: 18.2 t ADT: 15

FM

Fair

Over: SMALL STREAM

069182602, Appanoose, IA

Built 1961 Load: 18.2 t ADT: 130

FM

Fair

Over: WEST CEDAR

087310701, Calhoun, IA

Built 1955 Load: 18.2 t ADT: 5

BACKBONE ST PK

Fair

Over: MAQUOKETA RIVER

IN BACKBONE STATE PARK, Delaware, IA

Built 1976 Load: 18.2 t

140TH ST NE

Fair

Over: STREAM

081071603, Johnson, IA

Built 1977 Load: 18.2 t ADT: 663

LOCAL RD

Fair

Over: DRAINAGE

076290402, Madison, IA

Built 1962 Load: 18.2 t ADT: 15

NEST AVE

Fair

Over: OTTER CREEK OVERFLOW

098422802, Osceola, IA

Built 1954 Load: 18.2 t ADT: 103

LOCAL

Fair

Over: OTTER CREEK

098422902, Osceola, IA

Built 1949 Load: 18.2 t ADT: 41

LOCAL

Fair

Over: STREAM

099390901, Osceola, IA

Built 1954 Load: 18.2 t ADT: 46

LOCAL ROAD

Fair

Over: CAMP CREEK

079222305, Polk, IA

Built 1958 Load: 18.2 t ADT: 34

FM

Fair

Over: DRAINAGE

081220702, Polk, IA

Built 1967 Load: 18.2 t ADT: 439

LOCAL

Fair

Over: MCELHANEY CREEK

089431802, Woodbury, IA

Built 2007 Load: 18.2 t ADT: 50

LOCAL

Fair

Over: BR MUD CREEK

083102703, Benton, IA

Built 1972 Load: 18.3 t ADT: 15

LOCAL

Fair

Over: BR PRAIRIE CK

083112401, Benton, IA

Built 1978 Load: 18.3 t ADT: 50

LOCAL

Fair

Over: BR PRATT CK

086112602, Benton, IA

Built 1975 Load: 18.3 t ADT: 20

HARMON RD

Fair

Over: SPRING CREEK

87-11-27-01-10, Black Hawk, IA

Built 1948 Load: 18.3 t ADT: 39

HESS RD

Fair

Over: TRIB TO MILLER CREEK

87-13-25-02-10, Black Hawk, IA

Built 1961 Load: 18.3 t ADT: 20

E TAMA RD

Fair

Over: TRIB TO MILLER CREEK

87-13-35-01-10, Black Hawk, IA

Built 1974 Load: 18.3 t ADT: 314

FM

Fair

Over: ELK RUN CREEK

085340302, Carroll, IA

Built 1965 Load: 18.3 t ADT: 89

LOCAL

Fair

Over: BUFFALO CREEK

084392707, Crawford, IA

Built 1939 Load: 18.3 t ADT: 82

LOCAL

Fair

Over: CREEK

068121304, Davis, IA

Built 1959 Load: 18.3 t ADT: 34

LOCAL

Fair

Over: PRAIRIE CREEK

087E12306, Dubuque, IA

Built 1930 Load: 18.3 t ADT: 118

LOCAL ROAD

Fair

Over: SOLDIER RIVER

086402102, Ida, IA

Built 1967 Load: 18.3 t ADT: 11

FM

Fair

Over: CREEK

073083002, Jefferson, IA

Built 1950 Load: 18.3 t ADT: 50

SW OBSERVATORY

Fair

Over: BRANCH OF CROOKED CREEK

078062804, Johnson, IA

Built 1984 Load: 18.3 t ADT: 122

LOC 80TH AVE

Fair

Over: HINE CREEK

094291702, Kossuth, IA

Built 1987 Load: 18.3 t ADT: 15

LOC 80TH AVE

Fair

Over: HINE CREEK

094291702, Kossuth, IA

Built 1987 Load: 18.3 t ADT: 15

LOCAL

Fair

Over: BURNETT CR

085173301, Marshall, IA

Built 1940 Load: 18.3 t ADT: 47

LOCAL

Fair

Over: WATERMAN CREEK

094392305, O'Brien, IA

Built 1950 Load: 18.3 t ADT: 41

270TH ST

Fair

Over: WEST BR INDIAN CREEK

083223101, Story, IA

Built 1967 Load: 18.3 t ADT: 80

LOCAL

Fair

Over: CREEK

069352401, Taylor, IA

Built 1977 Load: 18.3 t ADT: 5

LOCAL

Fair

Over: BUTTRICK CREEK

086302901, Webster, IA

Built 1990 Load: 18.3 t ADT: 11

E MARQUIS RD

Fair

Over: TRIB TO CRANE CREEK

90-11-06-01-10, Black Hawk, IA

Built 2001 Load: 18.4 t ADT: 187

NOLAN AVE

Fair

Over: SAND CREEK

087082002, Buchanan, IA

Built 2012 Load: 18.4 t ADT: 30

MARSH AVE.

Fair

Over: SMALL STREAM

092161802, Butler, IA

Built 1961 Load: 18.4 t ADT: 82

LOCAL

Fair

Over: MIDDLE WILLOW CREEK

084413102, Crawford, IA

Built 2009 Load: 18.4 t ADT: 34

LOCAL

Fair

Over: STREAM

069242502, Decatur, IA

Built 1910 Load: 18.4 t ADT: 15

LOCAL

Fair

Over: STREAM

081090302, Iowa, IA

Built 1980 Load: 18.4 t ADT: 11

LOCAL RD

Fair

Over: SMITH CREEK

077091902, Keokuk, IA

Built 1997 Load: 18.4 t ADT: 71

FM

Fair

Over: SILVER CREEK

074413001, Pottawattamie, IA

Built 1958 Load: 18.4 t ADT: 79

LOCAL

Fair

Over: BRANCH OF SALT CREEK

084142804, Tama, IA

Built 1984 Load: 18.4 t ADT: 33

Showing 2,201-2,250 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.