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

Poor

Over: TURKEY RUN

074172402, Mahaska, IA

Built 1948 Load: 16.1 t ADT: 50

LOCAL

Poor

Over: MIDDLE TIMBER CREEK

083183402, Marshall, IA

Built 1938 Load: 16.1 t ADT: 16

FM

Poor

Over: IOWA RIVER

084172907, Marshall, IA

Built 1955 Load: 16.1 t ADT: 2,838

FM

Poor

Over: LITTLE SIOUX RIVER

084443003, Monona, IA

Built 1960 Load: 16.1 t ADT: 45

260TH STREET

Poor

Over: TARKIO RIVER

068383203, Page, IA

Built 1960 Load: 16.1 t ADT: 15

LOCAL

Poor

Over: STONY CREEK

080140306, Poweshiek, IA

Built 1923 Load: 16.1 t ADT: 26

FM

Poor

Over: WALNUT CREEK

074082303, Washington, IA

Built 1955 Load: 16.1 t ADT: 45

FM

Poor

Over: DD DIST 57

089271901, Webster, IA

Built 1978 Load: 16.1 t ADT: 1,197

FM

Poor

Over: DRAINAGE

089282401, Webster, IA

Built 1977 Load: 16.1 t ADT: 1,795

LOCAL

Poor

Over: CREEK

099072403, Winneshiek, IA

Built 1900 Load: 16.1 t ADT: 70

FM

Poor

Over: WHEELER CREEK

091231502, Wright, IA

Built 1968 Load: 16.1 t ADT: 199

LOCAL

Poor

Over: DD #219

092261201, Wright, IA

Built 1972 Load: 16.1 t ADT: 11

FM

Poor

Over: SMALL STREAM

091181802, Butler, IA

Built 1964 Load: 16.2 t ADT: 49

LOCAL

Poor

Over: DD 2

089332204, Calhoun, IA

Built 1975 Load: 16.2 t ADT: 26

LOCAL

Poor

Over: CREEK

089210206, Hardin, IA

Built 1990 Load: 16.2 t ADT: 62

FM 190TH ST

Poor

Over: WAPSIPINICON RIVER

097140801, Howard, IA

Built 1940 Load: 16.2 t ADT: 650

160TH ST

Poor

Over: DEEP CREEK

092440201, Plymouth, IA

Built 1900 Load: 16.2 t ADT: 71

EDISON LANE

Poor

Over: JORDAN CREEK

075392303, Pottawattamie, IA

Built 1976 Load: 16.2 t ADT: 5

IRR LOCAL

Poor

Over: RICHLAND CREEK

082152002, Tama, IA

Built 1956 Load: 16.2 t ADT: 33

LOCAL

Poor

Over: DAUGHERTY CREEK

068342805, Taylor, IA

Built 1953 Load: 16.2 t ADT: 60

LOCAL ROAD

Poor

Over: SMALL STREAM

076090802, Washington, IA

Built 1928 Load: 16.2 t ADT: 60

LOCAL

Poor

Over: BIG CREEK

082252902, Boone, IA

Built 1900 Load: 16.3 t ADT: 90

LOCAL

Poor

Over: PRAIRIE CREEK

084250402, Boone, IA

Built 1915 Load: 16.3 t ADT: 30

FM

Poor

Over: DD 82

086313201, Calhoun, IA

Built 1938 Load: 16.3 t ADT: 11

LOCAL RD

Poor

Over: CLEAR CREEK

082042907, Cedar, IA

Built 1946 Load: 16.3 t ADT: 71

LOCAL

Poor

Over: BR E FORK WAPSIPINICON

096130202, Chickasaw, IA

Built 1970 Load: 16.3 t ADT: 41

190TH AVE

Poor

Over: LINDSEY CREEK

090053304, Delaware, IA

Built 1920 Load: 16.3 t ADT: 20

20TH ST.

Poor

Over: HUNTER CREEK

091093101, Fayette, IA

Built 1998 Load: 16.3 t ADT: 34

LOCAL

Poor

Over: FLOOD CREEK

094162804, Floyd, IA

Built 1929 Load: 16.3 t ADT: 26

FM

Poor

Over: MUD CREEK

070051106, Henry, IA

Built 1972 Load: 16.3 t ADT: 70

FM

Poor

Over: SMALL

080102502, Iowa, IA

Built 1979 Load: 16.3 t ADT: 90

FM

Poor

Over: DUCK CREEK

086E42504, Jackson, IA

Built 1950 Load: 16.3 t ADT: 500

LOCAL

Poor

Over: BEAR CREEK

080182505, Jasper, IA

Built 1914 Load: 16.3 t ADT: 63

FM

Poor

Over: STREAM

076101101, Keokuk, IA

Built 1966 Load: 16.3 t ADT: 80

GRANITE AVE

Poor

Over: BROKEN KETTLE CREEK

093472202, Plymouth, IA

Built 1959 Load: 16.3 t ADT: 20

LOCAL

Poor

Over: OVER UPRR

079230508, Polk, IA

Built 1948 Load: 16.3 t ADT: 399

FM

Poor

Over: E FORK GRAND RIVER

067291906, Ringgold, IA

Built 1957 Load: 16.3 t ADT: 120

R35 10TH AVE

Poor

Over: NORTH RIVER

076250602, Warren, IA

Built 1962 Load: 16.3 t ADT: 260

FM

Poor

Over: NORTH RIVER

077253205, Warren, IA

Built 1960 Load: 16.3 t ADT: 60

LOCAL

Poor

Over: W FK LITTLE SIOUX RIVER

086450401, Woodbury, IA

Built 1952 Load: 16.3 t ADT: 30

FM

Poor

Over: CHARITON RIVER

067162005, Appanoose, IA

Built 1960 Load: 16.4 t ADT: 45

LOCAL

Poor

Over: WELDON RIVER

069241602, Decatur, IA

Built 1966 Load: 16.4 t ADT: 11

FM

Poor

Over: TRIB OF LITTLE RIVER

069253104, Decatur, IA

Built 1969 Load: 16.4 t ADT: 60

LOCAL

Poor

Over: BRUSH CREEK

069272603, Decatur, IA

Built 1920 Load: 16.4 t ADT: 21

FM

Poor

Over: DOWD CREEK, BRANCH

086182101, Grundy, IA

Built 1966 Load: 16.4 t ADT: 187

LOCAL

Poor

Over: SNIPE CREEK

081190401, Jasper, IA

Built 1921 Load: 16.4 t ADT: 51

FM

Poor

Over: SO SKUNK RIVER

075151108, Mahaska, IA

Built 1956 Load: 16.4 t ADT: 290

LOCAL

Poor

Over: LUTES CREEK

082170702, Marshall, IA

Built 1937 Load: 16.4 t ADT: 82

FM

Poor

Over: NAGEL DD

084440804, Monona, IA

Built 1960 Load: 16.4 t ADT: 79

LOCAL

Poor

Over: SMALL STREAM

086362601, Sac, IA

Built 1974 Load: 16.4 t ADT: 15

Showing 17,451-17,500 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.