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

Fair

Over: BRUSHY STREAM

081330701, Guthrie, IA

Built 1972 Load: 19.4 t ADT: 50

LOCAL

Fair

Over: STREAM

084E21105, Jackson, IA

Built 1998 Load: 19.4 t ADT: 157

SE 660TH ST

Fair

Over: PRAIRIE CR

077052901, Johnson, IA

Built 1930 Load: 19.4 t ADT: 26

W 295TH ST

Fair

Over: BR CLEAR CR

080081903, Johnson, IA

Built 1977 Load: 19.4 t ADT: 60

140TH ST NW

Fair

Over: KNAPP CREEK

081081601, Johnson, IA

Built 1987 Load: 19.4 t ADT: 50

LOCAL RD

Fair

Over: CLANTON CREEK

074271007, Madison, IA

Built 1974 Load: 19.4 t ADT: 20

FM

Fair

Over: MIDDLE RIVER

075281510, Madison, IA

Built 1981 Load: 19.4 t ADT: 180

LOCAL

Fair

Over: CLEAR CREEK

082203303, Marshall, IA

Built 1971 Load: 19.4 t ADT: 35

FM

Fair

Over: WHITE CREEK

072190103, Monroe, IA

Built 1961 Load: 19.4 t ADT: 25

LOCAL

Fair

Over: WALNUT CREEK

073382002, Montgomery, IA

Built 1984 Load: 19.4 t ADT: 26

LOCAL

Fair

Over: OCHEYEDAN RIVER

097390102, O'Brien, IA

Built 1933 Load: 19.4 t ADT: 30

LOCAL RD

Fair

Over: LITTLE FLOYD RIVER

097412802, O'Brien, IA

Built 1959 Load: 19.4 t ADT: 50

LOCAL

Fair

Over: STREAM

095340201, Palo Alto, IA

Built 2004 Load: 19.4 t ADT: 30

FM

Fair

Over: GRAYBILL CREEK

074402501, Pottawattamie, IA

Built 1956 Load: 19.4 t ADT: 100

E. 32ND ST

Fair

Over: PHEASANT CREEK

000000000, Scott, IA

Built 1987 Load: 19.4 t ADT: 1,802

100TH ST

Fair

Over: LONG DICK CREEK

085230301, Story, IA

Built 1955 Load: 19.4 t ADT: 45

100TH ST

Fair

Over: LONG DICK CREEK

085230301, Story, IA

Built 1955 Load: 19.4 t ADT: 45

LOCAL

Fair

Over: SUGAR CREEK

083160408, Tama, IA

Built 1920 Load: 19.4 t ADT: 44

LOCAL

Fair

Over: WEST 102 RIVER

069350309, Taylor, IA

Built 1987 Load: 19.4 t ADT: 20

FM

Fair

Over: LITTLE FOX RIVER

067111204, Van Buren, IA

Built 1953 Load: 19.4 t ADT: 70

LOCAL

Fair

Over: REED'S CR

069082601, Van Buren, IA

Built 1940 Load: 19.4 t ADT: 51

LOCAL

Fair

Over: CREEK

070082201, Van Buren, IA

Built 1937 Load: 19.4 t ADT: 5

LOCAL ROAD

Fair

Over: OTTER CREEK

075230904, Warren, IA

Built 1969 Load: 19.4 t ADT: 51

LOCAL

Fair

Over: FORK DICK CREEK

069221801, Wayne, IA

Built 1987 Load: 19.4 t ADT: 30

FM

Fair

Over: BOONE RIVER

090260901, Wright, IA

Built 1974 Load: 19.4 t ADT: 71

250TH ST

Fair

Over: BOONE RIVER

091261705, Wright, IA

Built 1974 Load: 19.4 t ADT: 90

LOCAL

Fair

Over: BOONE RIVER

091261805, Wright, IA

Built 1978 Load: 19.4 t ADT: 62

LOCAL

Fair

Over: SMALL STREAM

088072703, Buchanan, IA

Built 2005 Load: 19.5 t ADT: 39

FM

Fair

Over: SMALL STREAM

092181105, Butler, IA

Built 1953 Load: 19.5 t ADT: 34

LOCAL

Fair

Over: PURGATORY CREEK

085332503, Carroll, IA

Built 1900 Load: 19.5 t

FM

Fair

Over: DICKENSON BRANCH

067261104, Decatur, IA

Built 1963 Load: 19.5 t ADT: 329

283 RD

Fair

Over: RACCOON RIVER

082300103, Greene, IA

Built 1937 Load: 19.5 t ADT: 50

W AVE / P46

Fair

Over: WEST BEAVER CREEK

083290204, Greene, IA

Built 1924 Load: 19.5 t ADT: 329

LOCAL

Fair

Over: LONG DICK CR

086231601, Hamilton, IA

Built 1955 Load: 19.5 t ADT: 15

LOCAL

Fair

Over: LONG DICK CR

086232101, Hamilton, IA

Built 1955 Load: 19.5 t ADT: 26

LOCAL

Fair

Over: KEIGLEY CREEK

086243002, Hamilton, IA

Built 1955 Load: 19.5 t ADT: 20

LOCAL

Fair

Over: KEIGLEY CR

086243202, Hamilton, IA

Built 1954 Load: 19.5 t ADT: 15

FM

Fair

Over: SKUNK RIVER

087241201, Hamilton, IA

Built 1955 Load: 19.5 t ADT: 26

LOCAL

Fair

Over: SKUNK RIVER

087241202, Hamilton, IA

Built 1955 Load: 19.5 t ADT: 20

LOCAL

Fair

Over: BITTER CREEK

089411704, Ida, IA

Built 1967 Load: 19.5 t ADT: 41

FM

Fair

Over: WALNUT CREEK

073082704, Jefferson, IA

Built 1936 Load: 19.5 t ADT: 360

25TH AVE

Fair

Over: LOSS CREEK

086011105, Jones, IA

Built 1967 Load: 19.5 t ADT: 11

FM

Fair

Over: BIG CEDAR CREEK

090342704, Pocahontas, IA

Built 1964 Load: 19.5 t ADT: 649

LOCAL ROAD

Fair

Over: OLD CHANNEL

081223201, Polk, IA

Built 1969 Load: 19.5 t ADT: 60

FM

Fair

Over: SMALL CREEK

088370802, Sac, IA

Built 1919 Load: 19.5 t ADT: 26

260TH ST

Fair

Over: CLEAR CREEK

083212501, Story, IA

Built 1968 Load: 19.5 t ADT: 40

LOCAL

Fair

Over: RICHLAND CREEK

082141407, Tama, IA

Built 1920 Load: 19.5 t ADT: 33

LOCAL

Fair

Over: MIDDLE 102 RIVER

068340302, Taylor, IA

Built 1945 Load: 19.5 t ADT: 5

FM

Fair

Over: WEST 102 RIVER

068352705, Taylor, IA

Built 1956 Load: 19.5 t ADT: 15

LOCAL ROAD

Fair

Over: LIME STONE CREEK

074252101, Warren, IA

Built 1974 Load: 19.5 t ADT: 5

Showing 2,451-2,500 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.