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: WILDCAT CREEK

084091701, Benton, IA

Built 1987 Load: 29.8 t ADT: 1,100

FM

Fair

Over: ROCK CREEK

086110503, Benton, IA

Built 1987 Load: 29.8 t ADT: 70

SB I-380

Fair

Over: POYNER CREEK

0.2 MI. N OF JCT. SR V49, Black Hawk, IA

Built 1983 Load: 29.8 t ADT: 13,450

LOCAL

Fair

Over: WEST BRANCH OF PINE CRK

089082003, Buchanan, IA

Built 1988 Load: 29.8 t ADT: 62

FM

Fair

Over: NORTH BEAVER CREEK

090181502, Butler, IA

Built 1985 Load: 29.8 t ADT: 501

FM

Fair

Over: OVERFLOW TO W FORK CED R

092182104, Butler, IA

Built 1985 Load: 29.8 t ADT: 619

LOCAL

Fair

Over: CEDAR CREEK

086322601, Calhoun, IA

Built 1980 Load: 29.8 t ADT: 11

MARBLE RD

Fair

Over: LITTLE TURKEY RIVER

091021707, Clayton, IA

Built 1979 Load: 29.8 t ADT: 62

HORSESHOE RD

Fair

Over: STEELES CREEK

091042605, Clayton, IA

Built 1953 Load: 29.8 t ADT: 59

197TH ST

Fair

Over: CHERRY CREEK

082E42405, Clinton, IA

Built 1980 Load: 29.8 t ADT: 73

FM

Fair

Over: SALT CREEK

070121705, Davis, IA

Built 1972 Load: 29.8 t ADT: 35

NB I-35

Fair

Over: GRAND RIVER

3.1 mi. N of Jct. US 69, Decatur, IA

Built 1970 Load: 29.8 t ADT: 7,550

205 AVE

Fair

Over: SPRING CREEK

089053504, Delaware, IA

Built 1975 Load: 29.8 t ADT: 295

FM

Fair

Over: KIDDER CREEK

088010204, Dubuque, IA

Built 1985 Load: 29.8 t ADT: 619

FM

Fair

Over: MAQUOKETA RIVER

089020507, Dubuque, IA

Built 1984 Load: 29.8 t ADT: 412

BELTLINE NW

Fair

Over: MAQUOKETA RIVER

BELTLINE NW - N FORK, Dubuque, IA

Built 1987 Load: 29.8 t ADT: 1,738

FM OLIVE AVE

Fair

Over: SPRING CREEK

092202102, Franklin, IA

Built 1983 Load: 29.8 t ADT: 1,031

US 30

Fair

Over: BUTTRICK CREEK

2.3 mi. W of jct. 144, Greene, IA

Built 1957 Load: 29.8 t ADT: 4,230

FM

Fair

Over: BLACK HAWK CREEK

088161502, Grundy, IA

Built 1984 Load: 29.8 t ADT: 29

LOCAL ROAD

Fair

Over: BRANCH RIVER CREEK

089161801, Grundy, IA

Built 1955 Load: 29.8 t ADT: 78

LOCAL

Fair

Over: DEER CREEK

078302002, Guthrie, IA

Built 1987 Load: 29.8 t ADT: 60

LOCAL

Fair

Over: SOUTH FORK IOWA RIVER

087201703, Hardin, IA

Built 1985 Load: 29.8 t ADT: 35

FM

Fair

Over: DRAINAGE DITCH

092270606, Humboldt, IA

Built 1940 Load: 29.8 t ADT: 170

FM

Fair

Over: MAPLE RIVER

087401202, Ida, IA

Built 1976 Load: 29.8 t ADT: 131

LOCAL

Fair

Over: HILTON CREEK

080100505, Iowa, IA

Built 1984 Load: 29.8 t ADT: 60

LEGION ST

Fair

Over: ELK CREEK

079181704, Jasper, IA

Built 1986 Load: 29.8 t ADT: 170

S 48TH AVE W

Fair

Over: CHERRY CREEK

079191703, Jasper, IA

Built 1980 Load: 29.8 t ADT: 166

FM

Fair

Over: ROCK CREEK LAKE

080170403, Jasper, IA

Built 1979 Load: 29.8 t ADT: 360

FM SAND RD

Fair

Over: PECHMAN CREEK

078062404, Johnson, IA

Built 1976 Load: 29.8 t ADT: 1,210

US 151 SB

Fair

Over: KITTY CREEK

1.1 mi. S of Jct. SR X-44, Jones, IA

Built 1960 Load: 29.8 t ADT: 6,100

FM

Fair

Over: GOOSE CREEK

076052904, Louisa, IA

Built 1982 Load: 29.8 t ADT: 25

IBEX AVE

Fair

Over: LITTLE ROCK RIVER

098451202, Lyon, IA

Built 1978 Load: 29.8 t ADT: 46

FM

Fair

Over: NORTH BRANCH NORTH RIVER

077282304, Madison, IA

Built 1984 Load: 29.8 t ADT: 60

FM

Fair

Over: OVERFLOW

084190205, Marshall, IA

Built 1984 Load: 29.8 t ADT: 69

LOCAL

Fair

Over: MCCANDLESS CLEGHORN DD

085462403, Monona, IA

Built 1971 Load: 29.8 t ADT: 50

WB US 34

Fair

Over: WEST NODAWAY RIVER

0.3 MI. W OF JCT. US 71, Montgomery, IA

Built 1970 Load: 29.8 t ADT: 1,325

LOCAL

Fair

Over: BIG SLOUGH CREEK

078043002, Muscatine, IA

Built 1985 Load: 29.8 t ADT: 50

EB I-680

Fair

Over: MISSOURI RIVER & CITY ST

@ NORTH OMAHA, NE, Pottawattamie, IA

Built 1952 Load: 29.8 t ADT: 9,150

LOCAL

Fair

Over: STREAM

079162401, Poweshiek, IA

Built 1957 Load: 29.8 t ADT: 15

LOCAL

Fair

Over: SMALL STREAM

087362402, Sac, IA

Built 1985 Load: 29.8 t ADT: 20

FM

Fair

Over: ROCK RIVER OVERFLOW

097462102, Sioux, IA

Built 1950 Load: 29.8 t ADT: 2,963

FM

Fair

Over: MIDDLE 102 RIVER

068340401, Taylor, IA

Built 1975 Load: 29.8 t ADT: 40

FM

Fair

Over: HONEY CREEK

069323202, Taylor, IA

Built 1986 Load: 29.8 t ADT: 390

LOCAL

Fair

Over: SMALL

070330702, Taylor, IA

Built 1976 Load: 29.8 t ADT: 11

FM

Fair

Over: BIG EAST FORK MEDICINE R

067221205, Wayne, IA

Built 1984 Load: 29.8 t ADT: 35

FM

Fair

Over: BIG FORK MEDICINE

067222403, Wayne, IA

Built 1987 Load: 29.8 t ADT: 10

FM

Fair

Over: JORDAN CREEK

069210101, Wayne, IA

Built 1984 Load: 29.8 t ADT: 40

IA 9

Fair

Over: DRY RUN CREEK

0.1 mi. W OF JCT. IA 52, Winneshiek, IA

Built 1945 Load: 29.8 t ADT: 3,880

LOCAL ROAD

Fair

Over: CREEK

098073208, Winneshiek, IA

Built 1966 Load: 29.8 t ADT: 70

FM

Fair

Over: TURKEY RIVER

098100702, Winneshiek, IA

Built 1985 Load: 29.8 t ADT: 98

Showing 5,351-5,400 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.