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: ELK CREEK

069270805, Decatur, IA

Built 2000 Load: 16.2 t ADT: 26

LOCAL

Fair

Over: DD

092291902, Humboldt, IA

Built 1900 Load: 16.2 t ADT: 100

LOCAL

Fair

Over: TETE DES MORTS CREEK

087E32204, Jackson, IA

Built 1981 Load: 16.2 t ADT: 50

FM

Fair

Over: OLD MAN'S CREEK

079083504, Johnson, IA

Built 1969 Load: 16.2 t ADT: 700

LCL-APPLEWOOD

Fair

Over: STREAM

073420301, Mills, IA

Built 1930 Load: 16.2 t ADT: 26

LOCAL

Fair

Over: INDIAN CREEK

073391703, Montgomery, IA

Built 1997 Load: 16.2 t ADT: 15

LOCAL

Fair

Over: LAMKIN CREEK

096422101, O'Brien, IA

Built 1945 Load: 16.2 t ADT: 35

400TH STREET

Fair

Over: STREAM

075402704, Pottawattamie, IA

Built 1973 Load: 16.2 t ADT: 29

HONEYSUCKLE RD

Fair

Over: STREAM

075420901, Pottawattamie, IA

Built 1985 Load: 16.2 t ADT: 15

ROSEWOOD ROAD

Fair

Over: STREAM

076400301, Pottawattamie, IA

Built 1955 Load: 16.2 t ADT: 15

LOCAL

Fair

Over: MIDDLE NODAWAY RIVER

074332402, Adair, IA

Built 1950 Load: 16.3 t ADT: 82

ORANGE AVENUE

Fair

Over: EAST NODAWAY RIVER

072332702, Adams, IA

Built 1957 Load: 16.3 t ADT: 45

LOCAL

Fair

Over: SOAP CREEK

070131502, Davis, IA

Built 1952 Load: 16.3 t ADT: 80

LOCAL 325 ST

Fair

Over: STREAM

087062503, Delaware, IA

Built 1975 Load: 16.3 t ADT: 26

LOCAL 330 ST

Fair

Over: SMALL STREAM

087063601, Delaware, IA

Built 1966 Load: 16.3 t ADT: 33

FM

Fair

Over: SMALL STREAM

071033303, Des Moines, IA

Built 1953 Load: 16.3 t ADT: 60

LOCAL

Fair

Over: DOLBEE CREEK

072023403, Des Moines, IA

Built 1950 Load: 16.3 t ADT: 35

H AVE

Fair

Over: DD 102

084310802, Greene, IA

Built 1977 Load: 16.3 t ADT: 26

LOCAL

Fair

Over: TRIB TO MASON CREEK

079323403, Guthrie, IA

Built 1959 Load: 16.3 t ADT: 11

LOCAL ROAD

Fair

Over: SPEARMAN BRANCH

071062709, Henry, IA

Built 1994 Load: 16.3 t ADT: 30

FM

Fair

Over: DRAINAGE

072081806, Jefferson, IA

Built 1950 Load: 16.3 t ADT: 60

LOCAL

Fair

Over: STREAM

077130901, Keokuk, IA

Built 1953 Load: 16.3 t ADT: 20

FM

Fair

Over: LOST CREEK

069043103, Lee, IA

Built 1949 Load: 16.3 t ADT: 120

FM

Fair

Over: LITTLE ROCK RIVER

098441602, Lyon, IA

Built 1950 Load: 16.3 t ADT: 50

FM

Fair

Over: COAL CREEK

074170104, Mahaska, IA

Built 1948 Load: 16.3 t ADT: 80

FM

Fair

Over: STREAM

075180606, Marion, IA

Built 1956 Load: 16.3 t ADT: 60

110TH ST

Fair

Over: FLOYD RIVER

093440703, Plymouth, IA

Built 1940 Load: 16.3 t ADT: 60

450TH STREET

Fair

Over: STREAM

076390304, Pottawattamie, IA

Built 1940 Load: 16.3 t ADT: 11

LOCAL

Fair

Over: WOLF CREEK

069301902, Ringgold, IA

Built 1936 Load: 16.3 t ADT: 40

300TH ST

Fair

Over: SMALL STREAM

082241303, Story, IA

Built 1963 Load: 16.3 t ADT: 100

630TH AVE

Fair

Over: EAST BR INDIAN CREEK

085222002, Story, IA

Built 1924 Load: 16.3 t ADT: 26

120TH ST

Fair

Over: KEIGLEY BRANCH

085241601, Story, IA

Built 1968 Load: 16.3 t ADT: 50

FM

Fair

Over: TRIB DES MOINES RIVER

069102308, Van Buren, IA

Built 1959 Load: 16.3 t ADT: 45

FM

Fair

Over: SOUTH CHARITON RIVER

069200502, Wayne, IA

Built 1955 Load: 16.3 t ADT: 26

LOCAL

Fair

Over: CEDAR CREEK

076132802, Keokuk, IA

Built 1994 Load: 16.4 t ADT: 15

LOCAL

Fair

Over: TRIB S FORK ENGLISH RVR

077131203, Keokuk, IA

Built 1996 Load: 16.4 t ADT: 20

FM

Fair

Over: OTTER CREEK

098420104, Osceola, IA

Built 1936 Load: 16.4 t ADT: 60

LOCAL

Fair

Over: LITTLE OCHEYEDAN RIVER

099401802, Osceola, IA

Built 1948 Load: 16.4 t ADT: 21

HICKORY ROAD

Fair

Over: STREAM

075421701, Pottawattamie, IA

Built 1954 Load: 16.4 t ADT: 29

LOCAL

Fair

Over: BR YELLOW RIVER

096060303, Allamakee, IA

Built 1964 Load: 16.5 t ADT: 29

LOCAL

Fair

Over: SMALL STREAM

090020902, Dubuque, IA

Built 1986 Load: 16.5 t ADT: 34

UNION AVE

Fair

Over: STREAM

078331902, Guthrie, IA

Built 1991 Load: 16.5 t ADT: 20

FM

Fair

Over: MOOREHEAD CREEK

087413101, Ida, IA

Built 1967 Load: 16.5 t ADT: 26

3RD ST

Fair

Over: SMALL STREAM

000000000, Johnson, IA

Built 1980 Load: 16.5 t ADT: 260

LOCAL SEC RD

Fair

Over: MCCREATH CR

095391701, O'Brien, IA

Built 1940 Load: 16.5 t ADT: 15

LOCAL

Fair

Over: OCHEYEDAN RIVER

098390602, Osceola, IA

Built 1952 Load: 16.5 t ADT: 35

LOCAL

Fair

Over: PLATTE BRANCH

067322003, Taylor, IA

Built 1957 Load: 16.5 t ADT: 11

LOCAL

Fair

Over: TRIB OF DES MOINES RIVER

067081106, Van Buren, IA

Built 1966 Load: 16.5 t ADT: 21

NETTLE

Fair

Over: STREAM

098202902, Worth, IA

Built 1955 Load: 16.5 t ADT: 35

H20 110TH STREET

Fair

Over: EAST NODAWAY RIVER

073320104, Adams, IA

Built 1980 Load: 16.6 t ADT: 40

Showing 1,651-1,700 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.