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: FLOYD RIVER

094441404, Sioux, IA

Built 1962 Load: 20.7 t ADT: 60

LOCAL

Fair

Over: FLOYD RIVER

094442203, Sioux, IA

Built 1963 Load: 20.7 t ADT: 30

LOCAL

Fair

Over: CREEK

070101702, Van Buren, IA

Built 1955 Load: 20.7 t ADT: 47

FM

Fair

Over: SO AVERY CREEK

072153006, Wapello, IA

Built 1960 Load: 20.7 t ADT: 1,200

CO RD 105

Fair

Over: ELK CREEK

100203101, Worth, IA

Built 1950 Load: 20.7 t ADT: 1,414

IA 3

Fair

Over: IOWA RIVER

1.6 mi. E of E jct. US 69, Wright, IA

Built 1976 Load: 20.7 t ADT: 1,620

LOCAL

Fair

Over: CREEK

080362104, Audubon, IA

Built 1928 Load: 20.8 t ADT: 15

BARNES FERRY RD

Fair

Over: TRIB TO CEDAR RIVER

87-11-20-06-10, Black Hawk, IA

Built 1978 Load: 20.8 t ADT: 334

320TH ST

Fair

Over: STREAM

079042703, Cedar, IA

Built 1940 Load: 20.8 t ADT: 15

290TH ST

Fair

Over: OLD SKUNK RIVER CHANNEL

082230907, Story, IA

Built 1937 Load: 20.8 t ADT: 80

E18/130TH ST

Fair

Over: KEIGLEY BRANCH

085242101, Story, IA

Built 1967 Load: 20.8 t ADT: 1,427

LOCAL

Fair

Over: DEER CREEK

077233108, Warren, IA

Built 1950 Load: 20.8 t ADT: 30

LOCAL

Fair

Over: CROOKED CREEK

078343502, Audubon, IA

Built 1900 Load: 20.9 t ADT: 5

LOCAL

Fair

Over: SMALL STREAM

091152502, Butler, IA

Built 1966 Load: 20.9 t ADT: 21

LOCAL

Fair

Over: DRAINAGE DITCH #73

083340705, Carroll, IA

Built 1982 Load: 20.9 t ADT: 11

LOCAL-500TH ST

Fair

Over: SMALL CREEK

092391601, Cherokee, IA

Built 1925 Load: 20.9 t ADT: 26

LOCAL

Fair

Over: SMALL

094131802, Chickasaw, IA

Built 1978 Load: 20.9 t ADT: 49

137TH ST

Fair

Over: SMALL STREAM

090042303, Delaware, IA

Built 1939 Load: 20.9 t ADT: 44

185 TH

Fair

Over: OTTER CREEK

084321803, Greene, IA

Built 1992 Load: 20.9 t ADT: 30

LOCAL

Fair

Over: STREAM

078300204, Guthrie, IA

Built 1947 Load: 20.9 t ADT: 20

HICKORY AVE

Fair

Over: SOUTH FORK MIDDLE RIVER

078332502, Guthrie, IA

Built 1977 Load: 20.9 t ADT: 60

QUARRY LANE

Fair

Over: STREAM

079312611, Guthrie, IA

Built 1940 Load: 20.9 t ADT: 11

US 6

Fair

Over: RALSTON CREEK

0.3 MI. E OF E JCT. IA #1, Johnson, IA

Built 1957 Load: 20.9 t ADT: 27,000

BALSAM AVE

Fair

Over: CREEK

100182004, Mitchell, IA

Built 1930 Load: 20.9 t ADT: 20

FM

Fair

Over: MCCANDLESS CLEGHORN

084462301, Monona, IA

Built 1959 Load: 20.9 t ADT: 29

COUNTY ROAD

Fair

Over: BRANCH TARKIO CREEK

071372005, Montgomery, IA

Built 1959 Load: 20.9 t ADT: 11

LOCAL

Fair

Over: LITTLE OCHEYEDAN RIVER

099401901, Osceola, IA

Built 1939 Load: 20.9 t ADT: 30

FM

Fair

Over: STREAM

078141302, Poweshiek, IA

Built 1995 Load: 20.9 t ADT: 25

FM

Fair

Over: LOTTS CREEK

069283101, Ringgold, IA

Built 1941 Load: 20.9 t ADT: 26

250TH ST

Fair

Over: GRANT 5 OPEN DITCH

083232203, Story, IA

Built 1960 Load: 20.9 t ADT: 60

LOCAL

Fair

Over: ROCK CREEK

085131101, Tama, IA

Built 1966 Load: 20.9 t ADT: 20

LOCAL

Fair

Over: SALT CREEK

085153401, Tama, IA

Built 1966 Load: 20.9 t ADT: 29

LOCAL

Fair

Over: STREAM

088470411, Woodbury, IA

Built 1998 Load: 20.9 t ADT: 40

LOCAL C AVE.

Fair

Over: WEST FORK LITTLE SIOUX

091422102, Cherokee, IA

Built 1977 Load: 21.0 t ADT: 20

LOCAL 430TH ST

Fair

Over: CREEK

093410103, Cherokee, IA

Built 1975 Load: 21.0 t ADT: 20

US 30

Fair

Over: OVER UP RR

0.6 mi. E of jct. SR Y4E, Clinton, IA

Built 1955 Load: 21.0 t ADT: 2,550

LOCAL

Fair

Over: COON CREEK

082380604, Crawford, IA

Built 1998 Load: 21.0 t ADT: 21

LOCAL

Fair

Over: EAST SOLDIER RIVER

084400702, Crawford, IA

Built 2010 Load: 21.0 t ADT: 41

B AVE

Fair

Over: SMALL STREAM

85411001, Crawford, IA

Built 2013 Load: 21.0 t ADT: 21

LOCAL

Fair

Over: LITTLE SIOUX RIVER

098371103, Dickinson, IA

Built 1964 Load: 21.0 t ADT: 26

LOCAL

Fair

Over: LITTLE SIOUX RIVER

098372701, Dickinson, IA

Built 1963 Load: 21.0 t ADT: 51

120 TH

Fair

Over: STREAM

085311401, Greene, IA

Built 1967 Load: 21.0 t ADT: 15

490 130TH ST

Fair

Over: BOONE RIVER

094262201, Hancock, IA

Built 1979 Load: 21.0 t ADT: 40

1190 220TH ST

Fair

Over: DD #1 & 2

095250201, Hancock, IA

Built 1973 Load: 21.0 t ADT: 81

FM 1320 290TH

Fair

Over: DRAINAGE DITCH 1&2

097243101, Hancock, IA

Built 1983 Load: 21.0 t ADT: 46

FM 1640 290TH

Fair

Over: EAST BRANCH IOWA RIVER

097243401, Hancock, IA

Built 1982 Load: 21.0 t ADT: 26

FEDERAL AVE

Fair

Over: SUGAR CREEK

080213513, Jasper, IA

Built 1958 Load: 21.0 t ADT: 330

LOCAL

Fair

Over: BRUSH CREEK

072082802, Jefferson, IA

Built 1970 Load: 21.0 t ADT: 26

LOCAL

Fair

Over: CROW CREEK

072093104, Jefferson, IA

Built 1975 Load: 21.0 t ADT: 110

LOCAL

Fair

Over: STREAM

073091708, Jefferson, IA

Built 1972 Load: 21.0 t ADT: 26

Showing 2,801-2,850 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.