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: LOST WATER CREEK

097182902, Floyd, IA

Built 1996 Load: 13.5 t ADT: 874

NATURE AVE

Fair

Over: PLYMOUTH CREEK

092452502, Plymouth, IA

Built 1940 Load: 13.5 t ADT: 45

FM

Fair

Over: FOUR MILE CREEK

081242201, Polk, IA

Built 1965 Load: 13.5 t ADT: 912

FM

Fair

Over: INDIAN CREEK

087360701, Sac, IA

Built 1917 Load: 13.5 t ADT: 20

240TH ST

Fair

Over: DRAINAGE DITCH 14

091241701, Wright, IA

Built 1920 Load: 13.5 t ADT: 46

LOCAL

Fair

Over: STREAM

077311401, Adair, IA

Built 1938 Load: 13.6 t ADT: 15

IA 150

Fair

Over: STREAM

1.6 mi. N jct. SR E16, Benton, IA

Built 1940 Load: 13.6 t ADT: 3,330

105TH

Fair

Over: BEAVER DAM CREEK

094203507, Cerro Gordo, IA

Built 1959 Load: 13.6 t ADT: 11

HARVEST RD

Fair

Over: STREAM

091041006, Clayton, IA

Built 1920 Load: 13.6 t ADT: 21

3RD AVE (EXT)

Fair

Over: BEEDS CREEK

000000000, Franklin, IA

Built 1900 Load: 13.6 t ADT: 10

IA 1

Fair

Over: CROW CREEK

0.7 mi. N of jct SR W21, Jefferson, IA

Built 1928 Load: 13.6 t ADT: 4,100

CAMEO AVE

Fair

Over: CREEK

100182802, Mitchell, IA

Built 1919 Load: 13.6 t ADT: 285

LOCAL RD

Fair

Over: DEER CREEK

080230903, Polk, IA

Built 1976 Load: 13.6 t ADT: 60

LOCAL ROAD

Fair

Over: BR. WHITE OAK CK

081230901, Polk, IA

Built 1946 Load: 13.6 t ADT: 45

FM

Fair

Over: BR BIG CREEK

081251402, Polk, IA

Built 1931 Load: 13.6 t ADT: 259

IA 83

Fair

Over: DRAINAGE DITCH

1.3 MI. E OF E JCT SR M47, Pottawattamie, IA

Built 1936 Load: 13.6 t ADT: 770

IDELWOOD ROAD

Fair

Over: GRAYBILL CREEK

075390301, Pottawattamie, IA

Built 1948 Load: 13.6 t ADT: 15

IA 85

Fair

Over: DRAINAGE DITCH

0.7 MILES E OF SR V21, Poweshiek, IA

Built 1957 Load: 13.6 t ADT: 800

US 63

Fair

Over: STREAM

4.4 mi. N of SR G17, Poweshiek, IA

Built 1922 Load: 13.6 t ADT: 1,500

170TH ST

Fair

Over: LITTLE MINERVA CREEK

084211101, Story, IA

Built 1958 Load: 13.6 t ADT: 11

567TH AVE

Fair

Over: LONG DICK CREEK

085231806, Story, IA

Built 1911 Load: 13.6 t ADT: 80

550TH AVE

Fair

Over: KEIGLEY BRANCH

085243602, Story, IA

Built 1913 Load: 13.6 t ADT: 80

LOCAL

Fair

Over: STREAM

070101405, Van Buren, IA

Built 1955 Load: 13.6 t ADT: 30

290TH ST

Fair

Over: CROOKED CREEK

087280903, Webster, IA

Built 1950 Load: 13.6 t ADT: 499

LOCAL

Fair

Over: DRAINAGE

098080506, Winneshiek, IA

Built 1931 Load: 13.6 t ADT: 1,090

LOCAL

Fair

Over: NORTH BEAR CREEK

100072303, Winneshiek, IA

Built 1900 Load: 13.6 t ADT: 78

LOCAL

Fair

Over: BIG CEDAR CR D D 181

089342802, Calhoun, IA

Built 1921 Load: 13.7 t ADT: 20

LOCAL

Fair

Over: FIELD STREAM

084361301, Carroll, IA

Built 1938 Load: 13.7 t ADT: 5

FM

Fair

Over: VESSER CREEK

070121304, Davis, IA

Built 1948 Load: 13.7 t ADT: 150

SPRUCE RD

Fair

Over: LITTLE TURKEY RIVER

095102504, Fayette, IA

Built 1964 Load: 13.7 t ADT: 49

LOCAL

Fair

Over: STREAM

100420901, Osceola, IA

Built 1900 Load: 13.7 t ADT: 26

215TH ST

Fair

Over: WAPSIPINICON RIVER

092113203, Bremer, IA

Built 1969 Load: 13.8 t ADT: 29

JOPLIN AVE

Fair

Over: QUARTER SECTION RUN

092131502, Bremer, IA

Built 1993 Load: 13.8 t ADT: 26

IRONWOOD RD.

Fair

Over: TURKEY RIVER

095082304, Fayette, IA

Built 1965 Load: 13.8 t ADT: 25

140TH ST

Fair

Over: ALLEN CREEK

081432601, Harrison, IA

Built 1973 Load: 13.8 t ADT: 15

LCL-NOYES AVE

Fair

Over: DEER CREEK

071401001, Mills, IA

Built 1950 Load: 13.8 t ADT: 11

NB US 75

Fair

Over: FLAT CREEK

1.2 mi. S of SR C44, Plymouth, IA

Built 1972 Load: 13.8 t ADT: 7,000

LOCAL

Fair

Over: PRAIRIE CR

089070402, Buchanan, IA

Built 1953 Load: 13.9 t ADT: 16

LOCAL

Fair

Over: PRAIRIE CR

089070902, Buchanan, IA

Built 1953 Load: 13.9 t ADT: 30

SCOTT ST

Fair

Over: SMALL CREEK

073241101, Clarke, IA

Built 2008 Load: 13.9 t ADT: 40

LOCAL

Fair

Over: JONATHAN CREEK

070243102, Decatur, IA

Built 1965 Load: 13.9 t ADT: 35

W.CHARLES ST

Fair

Over: OTTER CREEK

000000000, Fayette, IA

Built 1950 Load: 13.9 t ADT: 571

LOCAL

Fair

Over: BROADHORN CREEK

074260104, Madison, IA

Built 1985 Load: 13.9 t ADT: 26

290TH STREET

Fair

Over: BUCHANAN CREEK

067361503, Page, IA

Built 1981 Load: 13.9 t ADT: 29

LOCAL

Fair

Over: STREAM

097312901, Palo Alto, IA

Built 1928 Load: 13.9 t ADT: 36

460TH STREET

Fair

Over: GRAYBILL CREEK

076392203, Pottawattamie, IA

Built 1994 Load: 13.9 t ADT: 11

LOCAL

Fair

Over: ELM CREEK

079370801, Shelby, IA

Built 2000 Load: 13.9 t ADT: 30

LOCAL

Fair

Over: PLATTE BRANCH

068321504, Taylor, IA

Built 1963 Load: 13.9 t ADT: 20

IA 281

Fair

Over: POYNER CREEK

1.9 Mi. E OF Jct. SR V49, Black Hawk, IA

Built 1951 Load: 14.0 t ADT: 1,080

LOCAL

Fair

Over: STREAM

074202402, Marion, IA

Built 1973 Load: 14.0 t ADT: 16

Showing 1,301-1,350 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.