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: NORTH TURKEY CREEK

077313303, Adair, IA

Built 2006 Load: 21.4 t ADT: 11

ADAMS-CASS ST

Fair

Over: STREAM

073350301, Adams, IA

Built 1999 Load: 21.4 t ADT: 5

LOCAL

Fair

Over: WEST NISHNABOTNA RIVER

082363102, Carroll, IA

Built 1968 Load: 21.4 t ADT: 79

LOCAL

Fair

Over: FIELD STREAM

083361602, Carroll, IA

Built 1977 Load: 21.4 t ADT: 11

FM

Fair

Over: BRUSHY FORK CREEK

084362402, Carroll, IA

Built 1976 Load: 21.4 t ADT: 50

J 20 AGENCY RD

Fair

Over: SPILLWAY

069050103, Des Moines, IA

Built 1935 Load: 21.4 t ADT: 400

LOCAL

Fair

Over: STREAM

087E10607, Dubuque, IA

Built 1981 Load: 21.4 t ADT: 15

LOCAL

Fair

Over: LYTLE CREEK

087E21802, Dubuque, IA

Built 1981 Load: 21.4 t ADT: 45

160 STREET

Fair

Over: HUNTER BRANCH

069400501, Fremont, IA

Built 1975 Load: 21.4 t ADT: 21

LCL-WAUBONSIE

Fair

Over: HUNTERS CREEK

070400301, Fremont, IA

Built 1968 Load: 21.4 t ADT: 40

310 AVENUE

Fair

Over: DRISCOLL CREEK

070410802, Fremont, IA

Built 1963 Load: 21.4 t ADT: 10

LOCAL

Fair

Over: DRAINAGE DITCH

089230902, Hamilton, IA

Built 1924 Load: 21.4 t ADT: 26

FM & 155TH ST

Fair

Over: MUD CREEK

081423605, Harrison, IA

Built 1940 Load: 21.4 t ADT: 79

LOCAL

Fair

Over: DD

093272001, Humboldt, IA

Built 1900 Load: 21.4 t ADT: 15

182 AVE

Fair

Over: DRAINAGE DITCH

084E21204, Jackson, IA

Built 1997 Load: 21.4 t ADT: 550

US 6

Fair

Over: IOWA RIVER

0.2 MI. E OF E JCT. IA 1, Johnson, IA

Built 1957 Load: 21.4 t ADT: 27,000

228TH AVE.

Fair

Over: DUTCH CREEK

084042104, Jones, IA

Built 2008 Load: 21.4 t ADT: 21

140TH AVE.

Fair

Over: SMALL CREEK

085031202, Jones, IA

Built 1974 Load: 21.4 t ADT: 25

K14 BEECH AVE

Fair

Over: PLUM CREEK

098480306, Lyon, IA

Built 1977 Load: 21.4 t ADT: 41

FM

Fair

Over: STREAM

077271404, Madison, IA

Built 1960 Load: 21.4 t ADT: 71

FA-LEVI ROAD

Fair

Over: STREAM

072433606, Mills, IA

Built 1966 Load: 21.4 t ADT: 219

LOCAL SEC RD

Fair

Over: STOFFERAN CREEK

095 42 04 02, O'Brien, IA

Built 2010 Load: 21.4 t ADT: 26

FM C-16

Fair

Over: DEEP CREEK

093432101, Plymouth, IA

Built 1960 Load: 21.4 t ADT: 409

NW MADRID DR.

Fair

Over: BIG CREEK DIV.CHL

081253504, Polk, IA

Built 1970 Load: 21.4 t ADT: 1,314

FM

Fair

Over: SILVER CREEK

078402603, Shelby, IA

Built 1914 Load: 21.4 t ADT: 41

LOCAL

Fair

Over: BUCK CREEK

079371202, Shelby, IA

Built 1955 Load: 21.4 t ADT: 35

LOCAL

Fair

Over: GREELEY CREEK

081381303, Shelby, IA

Built 1993 Load: 21.4 t ADT: 11

FM

Fair

Over: BRANCH CEDAR CREEK

073132108, Wapello, IA

Built 1962 Load: 21.4 t ADT: 210

LOCAL ROAD

Fair

Over: TROUT CREEK

097080804, Winneshiek, IA

Built 1900 Load: 21.4 t ADT: 29

LOCAL

Fair

Over: CREEK

080362401, Audubon, IA

Built 1936 Load: 21.5 t ADT: 91

FM

Fair

Over: PURGATORY CREEK

087321101, Calhoun, IA

Built 1955 Load: 21.5 t ADT: 26

LOCAL

Fair

Over: LITTLE WAPSIPINICON RVR

095130401, Chickasaw, IA

Built 1959 Load: 21.5 t ADT: 62

EDGE RD

Fair

Over: UNAMED CREEK

094070804, Fayette, IA

Built 2020 Load: 21.5 t ADT: 20

LOCAL RD

Fair

Over: OCHEYEDAN RIVER

100403002, Osceola, IA

Built 1942 Load: 21.5 t ADT: 11

FM

Fair

Over: MINK CREEK

093461502, Plymouth, IA

Built 1961 Load: 21.5 t ADT: 559

ASPEN ROAD

Fair

Over: STREAM

074413403, Pottawattamie, IA

Built 1998 Load: 21.5 t ADT: 5

390TH STREET

Fair

Over: STREAM

076401002, Pottawattamie, IA

Built 1951 Load: 21.5 t ADT: 5

FM

Fair

Over: PORTER CREEK

086383504, Sac, IA

Built 1960 Load: 21.5 t ADT: 100

FM

Fair

Over: DEER CREEK

090301101, Webster, IA

Built 1946 Load: 21.5 t ADT: 50

LOCAL

Fair

Over: NINE MILE CREEK

075330301, Adair, IA

Built 1993 Load: 21.6 t ADT: 26

FM-FILBERT AVE

Fair

Over: MIDDLE NODAWAY RIVER

072340702, Adams, IA

Built 1974 Load: 21.6 t ADT: 45

LOCAL - 740TH

Fair

Over: STALE BRANCH

074343302, Cass, IA

Built 1948 Load: 21.6 t ADT: 5

LOCAL ROAD

Fair

Over: WATERWAY

075342302, Cass, IA

Built 1990 Load: 21.6 t ADT: 15

JONQUIL

Fair

Over: CALMUS CREEK

097212702, Cerro Gordo, IA

Built 1974 Load: 21.6 t ADT: 41

US 18

Fair

Over: EAST WAPSIPINICON RIVER

0.3 mi. W of Jct S.R. V48, Chickasaw, IA

Built 1983 Load: 21.6 t ADT: 3,150

LOCAL

Fair

Over: LITTLE WAPSIPINICON RVR

096133201, Chickasaw, IA

Built 1980 Load: 21.6 t ADT: 26

LOCAL

Fair

Over: WAPSIPINICON RIVER

096140503, Chickasaw, IA

Built 1973 Load: 21.6 t ADT: 21

LOCAL

Fair

Over: COON CREEK

083393602, Crawford, IA

Built 1973 Load: 21.6 t ADT: 11

LOCAL

Fair

Over: SMALL DRAINAGE

085390201, Crawford, IA

Built 1976 Load: 21.6 t ADT: 21

FM-BLACKHAWK AV

Fair

Over: CLEAR CREEK

080082904, Johnson, IA

Built 1995 Load: 21.6 t ADT: 1,200

Showing 3,001-3,050 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.