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

BLUFF ROAD

Fair

Over: WAUBONSIE DITCH

070431106, Fremont, IA

Built 1955 Load: 27.8 t ADT: 142

170 TH

Fair

Over: STREAM

084311003, Greene, IA

Built 1972 Load: 27.8 t ADT: 15

US 218 NB

Fair

Over: SOUTH FISH CREEK

0.7 mi. N of Jct. SR J20, Henry, IA

Built 1964 Load: 27.8 t ADT: 4,850

IA # 78

Fair

Over: STREAM

2.0 mi. W of W Jct W-66, Henry, IA

Built 1916 Load: 27.8 t ADT: 1,110

SPENCER ST

Fair

Over: SOUTH SKUNK R. OVERFLOW

078183002, Jasper, IA

Built 1986 Load: 27.8 t ADT: 50

LOCAL

Fair

Over: INDIAN CREEK

080200702, Jasper, IA

Built 1987 Load: 27.8 t ADT: 91

LOCAL

Fair

Over: STREAM

074113403, Keokuk, IA

Built 1972 Load: 27.8 t ADT: 15

IA 13

Fair

Over: HEATON'S CREEK

2.6 mi. S of S Jct SR D62, Linn, IA

Built 1976 Load: 27.8 t ADT: 5,600

MT.VERNON RD

Fair

Over: BIG CREEK

083062601, Linn, IA

Built 1984 Load: 27.8 t ADT: 1,669

US 65

Fair

Over: CHARITON RIVER

2.2 MI. N OF Jct. SR H50, Lucas, IA

Built 1991 Load: 27.8 t ADT: 1,260

LOCAL

Fair

Over: DRAINAGE

075291103, Madison, IA

Built 1988 Load: 27.8 t ADT: 71

FM

Fair

Over: ENGLISH

075181306, Marion, IA

Built 1980 Load: 27.8 t ADT: 440

FM

Fair

Over: ROCK CREEK

084172702, Marshall, IA

Built 1971 Load: 27.8 t ADT: 1,964

US 34

Fair

Over: OVER BNSF RR

0.9 MI. E JCT. SR L-55, Mills, IA

Built 1966 Load: 27.8 t ADT: 6,000

E41/LINCOLN HWY

Fair

Over: E BR INDIAN CR & RR

083221005, Story, IA

Built 1973 Load: 27.8 t ADT: 1,048

670TH AVE

Fair

Over: HICKORY GROVE LK OUTLET

083222402, Story, IA

Built 1965 Load: 27.8 t ADT: 110

620TH AVE/S14

Fair

Over: GRANT OPEN DITCH EXT 5

083223102, Story, IA

Built 1977 Load: 27.8 t ADT: 988

E63/730TH AVE

Fair

Over: WILLOW CREEK

082211302, Story, IA

Built 1972 Load: 27.8 t ADT: 131

FM

Fair

Over: MIDDLE 102 RIVER

067341801, Taylor, IA

Built 1986 Load: 27.8 t ADT: 210

FM

Fair

Over: D D

088300604, Webster, IA

Built 1975 Load: 27.8 t ADT: 578

LOCAL

Fair

Over: STREAM

0864408, Woodbury, IA

Built 2001 Load: 27.8 t ADT: 26

120TH ST

Fair

Over: MUD CREEK

089451303, Woodbury, IA

Built 1981 Load: 27.8 t ADT: 20

GARNER AVE

Fair

Over: STREAM

089452506, Woodbury, IA

Built 1985 Load: 27.8 t ADT: 15

LOCAL RD

Fair

Over: COTA CREEK

097031303, Allamakee, IA

Built 1991 Load: 27.9 t ADT: 49

LOCAL

Fair

Over: BRANCH PAINT CREEK

E55000510, Allamakee, IA

Built 1995 Load: 27.9 t ADT: 59

LOCAL

Fair

Over: PATTERSON CREEK

098060204, Allamakee, IA

Built 1941 Load: 27.9 t ADT: 60

FM 260TH AVE

Fair

Over: LITTLE SIOUX RIVER

095363502, Clay, IA

Built 1969 Load: 27.9 t ADT: 71

LOCAL

Fair

Over: SMALL DITCH

000000000, Clayton, IA

Built 1908 Load: 27.9 t ADT: 180

100TH ST.

Fair

Over: CREEK

083E30607, Clinton, IA

Built 1959 Load: 27.9 t ADT: 29

US 30 & 59

Fair

Over: OVER UP RR

0.4 mi E of W jct US 59, Crawford, IA

Built 1962 Load: 27.9 t ADT: 4,400

US 30 & 59

Fair

Over: EAST BOYER RIVER

0.4 mi. E of W jct. US 59, Crawford, IA

Built 1962 Load: 27.9 t ADT: 4,400

260 STREET

Fair

Over: MAIN DITCH

068433601, Fremont, IA

Built 1981 Load: 27.9 t ADT: 26

170 STREET

Fair

Over: SMALL STREAM

069400701, Fremont, IA

Built 1983 Load: 27.9 t ADT: 71

242 AVENUE

Fair

Over: POSSUM CREEK

069421902, Fremont, IA

Built 1980 Load: 27.9 t ADT: 240

325 AVENUE

Fair

Over: PERKINS CREEK

070412104, Fremont, IA

Built 1981 Load: 27.9 t ADT: 11

IA 44

Fair

Over: MIDDLE RACCOON RIVER

1.2 Mi. W of Jct. IA 4, Guthrie, IA

Built 1972 Load: 27.9 t ADT: 3,200

FM JAMES AVE

Fair

Over: BEAVER CREEK

100132704, Howard, IA

Built 1972 Load: 27.9 t ADT: 118

LOCAL

Fair

Over: CREEK

089401802, Ida, IA

Built 1970 Load: 27.9 t ADT: 35

LOCAL

Fair

Over: PLEASANT CREEK

085E41504, Jackson, IA

Built 1950 Load: 27.9 t ADT: 71

FM

Fair

Over: SMALL CREEK

086E10710, Jackson, IA

Built 1988 Load: 27.9 t ADT: 90

LANGWORTHY RD

Fair

Over: KITTY CREEK

085030508, Jones, IA

Built 1960 Load: 27.9 t ADT: 412

COUNTY RD X-64

Fair

Over: OVERFLOW

083012810, Jones, IA

Built 1950 Load: 27.9 t ADT: 393

MT VERNON RD

Fair

Over: WANATEE CREEK

083062909, Linn, IA

Built 1969 Load: 27.9 t ADT: 7,169

LOCAL ROAD

Fair

Over: OTTER CREEK

098442800, Lyon, IA

Built 2010 Load: 27.9 t ADT: 35

FM

Fair

Over: PIKE CREEK

076041005, Muscatine, IA

Built 1986 Load: 27.9 t ADT: 550

FM

Fair

Over: WAPSINONOC CREEK

078043601, Muscatine, IA

Built 1982 Load: 27.9 t ADT: 110

270TH STREET

Fair

Over: TARKIO RIVER

067380503, Page, IA

Built 1977 Load: 27.9 t ADT: 303

LOCAL

Fair

Over: LITTLE CEDAR CREEK

091341901, Pocahontas, IA

Built 1969 Load: 27.9 t ADT: 26

YORK ROAD

Fair

Over: DRAINAGE

077400501, Pottawattamie, IA

Built 1966 Load: 27.9 t ADT: 71

FM

Fair

Over: SPENCER CREEK

079E43201, Scott, IA

Built 1975 Load: 27.9 t ADT: 2,740

Showing 4,951-5,000 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.