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: CREEK

084E10504, Jackson, IA

Built 1990 Load: 34.0 t ADT: 44

FM

Fair

Over: FARMER'S CREEK

087E33306, Jackson, IA

Built 1979 Load: 34.0 t ADT: 380

LOWER OLD HWY 6

Fair

Over: STREAM

080082303, Johnson, IA

Built 1900 Load: 34.0 t ADT: 510

COUNTY RD E-53

Fair

Over: SMALL CREEK

083023201, Jones, IA

Built 1971 Load: 34.0 t ADT: 196

170TH ST

Fair

Over: BRANCH KITTY CREEK

085021801, Jones, IA

Built 2001 Load: 34.0 t ADT: 41

COUNTY RD E-16

Fair

Over: BRANCH OF WET CREEK

086043601, Jones, IA

Built 1968 Load: 34.0 t ADT: 727

LOCAL

Fair

Over: UNNAMED STREAM

076121203, Keokuk, IA

Built 1954 Load: 34.0 t ADT: 20

FM

Fair

Over: MUD CREEK

094420302, O'Brien, IA

Built 2002 Load: 34.0 t ADT: 878

330TH ST

Fair

Over: LITTLE FLOYD RIVER

096 42 01 10, O'Brien, IA

Built 2011 Load: 34.0 t ADT: 46

IA 48

Fair

Over: ROCKY BRANCH

1.2 MI. S OF SR M-41, Page, IA

Built 1969 Load: 34.0 t ADT: 2,380

LOCAL

Fair

Over: SMALL STREAM

095463201, Sioux, IA

Built 1959 Load: 34.0 t ADT: 50

FM

Fair

Over: SMALL

095451201, Sioux, IA

Built 1900 Load: 34.0 t ADT: 2,992

DOGWOOD

Fair

Over: BEAVER CREEK

098223404, Worth, IA

Built 2001 Load: 34.0 t ADT: 135

LOCAL

Fair

Over: CREEK

081351901, Audubon, IA

Built 1997 Load: 34.1 t ADT: 21

W TAMA RD

Fair

Over: GIVEN CREEK

87-14-32-01-10, Black Hawk, IA

Built 1985 Load: 34.1 t ADT: 49

LOCAL

Fair

Over: HARDIN CREEK

086310202, Calhoun, IA

Built 1987 Load: 34.1 t ADT: 15

FM

Fair

Over: DRAINAGE DITCH(LAKE CR)

089321402, Calhoun, IA

Built 1986 Load: 34.1 t ADT: 45

LOCAL

Fair

Over: DRAINAGE DITCH 1-54

089333201, Calhoun, IA

Built 1985 Load: 34.1 t ADT: 20

FM - INDIAN CRK

Fair

Over: TRIB INDIAN CREEK

076371904, Cass, IA

Built 1987 Load: 34.1 t ADT: 45

FINCH

Fair

Over: CREEK

094221302, Cerro Gordo, IA

Built 1978 Load: 34.1 t ADT: 15

FM

Fair

Over: S. FORK IOWA RIVER

087193002, Hardin, IA

Built 1978 Load: 34.1 t ADT: 88

IA 9

Fair

Over: MUD CREEK

1.7 mi. E of jct. SR P20, Kossuth, IA

Built 1931 Load: 34.1 t ADT: 1,570

LOCAL

Fair

Over: NISHNABOTNA TRIB

073370704, Montgomery, IA

Built 1968 Load: 34.1 t ADT: 89

US 6 & IA 38

Fair

Over: MUD CREEK

0.8 MI. E OF JCT IA 38, Muscatine, IA

Built 1924 Load: 34.1 t ADT: 5,100

FM

Fair

Over: GEDNEY LAKE

076041003, Muscatine, IA

Built 1975 Load: 34.1 t ADT: 550

OMEGA AVE

Fair

Over: CREEK

090441704, Plymouth, IA

Built 1900 Load: 34.1 t ADT: 5

FM-IDELWOOD RD

Fair

Over: SILVER CREEK

075410101, Pottawattamie, IA

Built 1974 Load: 34.1 t ADT: 34

FM

Fair

Over: RACOON RIVER

089362401, Sac, IA

Built 1972 Load: 34.1 t ADT: 290

IA 22

Fair

Over: DODGE CREEK

1.1 mi S. of Jct. SR Y48, Scott, IA

Built 1974 Load: 34.1 t ADT: 3,990

LOCAL

Fair

Over: EAGLE CREEK

091253103, Wright, IA

Built 1986 Load: 34.1 t ADT: 112

LOCAL

Fair

Over: BLACKHAWK CREEK

088161001, Grundy, IA

Built 1957 Load: 34.2 t ADT: 44

US 30

Fair

Over: WILLOW CREEK

0.6 MI. E OF JCT. I-29, Harrison, IA

Built 1972 Load: 34.2 t ADT: 10,300

LOCAL

Fair

Over: MCCANDLESS CLEGHORN DD

085462503, Monona, IA

Built 1970 Load: 34.2 t ADT: 40

FM

Fair

Over: TARKIO CREEK TRIB

073372603, Montgomery, IA

Built 1970 Load: 34.2 t ADT: 26

IA 83

Fair

Over: WALNUT CREEK

1.7 MI E of E JCT. SR M47, Pottawattamie, IA

Built 1996 Load: 34.2 t ADT: 770

IA 92

Fair

Over: FARM CREEK

6.3 MI. E OF JCT. 59, Pottawattamie, IA

Built 1957 Load: 34.2 t ADT: 1,180

LOCAL

Fair

Over: BOYER RIVER

090361602, Buena Vista, IA

Built 1996 Load: 34.3 t ADT: 26

LOCAL 240 ST

Fair

Over: SAND CREEK

088061401, Delaware, IA

Built 1985 Load: 34.3 t ADT: 88

FM 210TH AVE

Fair

Over: SMALL STREAM

089052502, Delaware, IA

Built 1984 Load: 34.3 t ADT: 29

LOC 200TH ST

Fair

Over: SPRING BRANCH

089062901, Delaware, IA

Built 1989 Load: 34.3 t ADT: 33

IA 333

Fair

Over: DRAINAGE DITCH

0.3 MI. E OF JCT.29, Fremont, IA

Built 1961 Load: 34.3 t ADT: 1,420

170 TH / E26

Fair

Over: EAST BUTTRICKS CREEK

084290801, Greene, IA

Built 1935 Load: 34.3 t ADT: 170

FM

Fair

Over: BOONE RIVER

087261406, Hamilton, IA

Built 1973 Load: 34.3 t ADT: 429

CO RD E 45

Fair

Over: CATFISH CREEK

083031005, Jones, IA

Built 2018 Load: 34.3 t ADT: 648

LANDIS RD.

Fair

Over: SMALL CREEK

084031704, Jones, IA

Built 1937 Load: 34.3 t ADT: 78

COUNTY RD X-44

Fair

Over: SMALL CREEK

085032202, Jones, IA

Built 2007 Load: 34.3 t ADT: 668

COUNTY RD X-31

Fair

Over: SAMS CREEK

085042204, Jones, IA

Built 1966 Load: 34.3 t ADT: 520

COUNTY RD D-62

Fair

Over: WET CREEK

086042409, Jones, IA

Built 1992 Load: 34.3 t ADT: 599

BLAIRSFERRY RD

Fair

Over: OTTER CREEK

084082604, Linn, IA

Built 1971 Load: 34.3 t ADT: 5,401

LCL-250TH ST

Fair

Over: MILLER CREEK

072420502, Mills, IA

Built 1978 Load: 34.3 t ADT: 45

Showing 7,401-7,450 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.