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

N UNION RD

Fair

Over: BEAVER CREEK OVERFLOW

90-14-28-06, Black Hawk, IA

Built 1980 Load: 31.2 t ADT: 1,394

FM

Fair

Over: LITTLE SPRING CREEK

088103106, Buchanan, IA

Built 1987 Load: 31.2 t ADT: 1,070

LOCAL

Fair

Over: HARDIN CREEK DD#95

086310201, Calhoun, IA

Built 1982 Load: 31.2 t ADT: 15

LOCAL

Fair

Over: D D NO 2

088341501, Calhoun, IA

Built 1980 Load: 31.2 t ADT: 30

LOCAL

Fair

Over: DRAINAGE DITCH 1-54

089333001, Calhoun, IA

Built 1982 Load: 31.2 t ADT: 15

FM

Fair

Over: DD #1-54

089333102, Calhoun, IA

Built 1982 Load: 31.2 t ADT: 20

LOCAL

Fair

Over: CREEK

080270202, Dallas, IA

Built 1925 Load: 31.2 t ADT: 35

COUNTY ROAD

Fair

Over: SLOUGH CREEK

080271403, Dallas, IA

Built 1927 Load: 31.2 t ADT: 26

COUNTY ROAD

Fair

Over: PANTHER CREEK

080283102, Dallas, IA

Built 1935 Load: 31.2 t ADT: 21

FM

Fair

Over: BROWN CREEK

100332901, Emmet, IA

Built 1981 Load: 31.2 t ADT: 409

IA 175

Fair

Over: BRANCH BLACKHAWK CREEK

0.8 MILE W OF JCT SR T69, Grundy, IA

Built 1977 Load: 31.2 t ADT: 2,080

FM

Fair

Over: HAMMERS CREEK

089151202, Grundy, IA

Built 1981 Load: 31.2 t ADT: 34

FM 640 120TH ST

Fair

Over: MID BR BOONE RIVER

094262501, Hancock, IA

Built 1988 Load: 31.2 t ADT: 518

FM 2040 ECHO AV

Fair

Over: BOONE RIVER

095261102, Hancock, IA

Built 1985 Load: 31.2 t ADT: 110

3330 AMES AVE

Fair

Over: BUFFALO CREEK

097260602, Hancock, IA

Built 1985 Load: 31.2 t ADT: 47

C ST RD

Fair

Over: S HOOSIER CR

082072604, Linn, IA

Built 1985 Load: 31.2 t ADT: 128

LOCAL

Fair

Over: DD#JT.63

094333501, Palo Alto, IA

Built 1985 Load: 31.2 t ADT: 62

LOCAL

Fair

Over: DD #61

095313501, Palo Alto, IA

Built 1980 Load: 31.2 t ADT: 41

FM

Fair

Over: S LIZARD CREEK DD#22

091333601, Pocahontas, IA

Built 1982 Load: 31.2 t ADT: 589

LOCAL

Fair

Over: BEAVER CREEK

093320401, Pocahontas, IA

Built 1982 Load: 31.2 t ADT: 5

FM

Fair

Over: PILOT CREEK (DD#63)

093331301, Pocahontas, IA

Built 1986 Load: 31.2 t ADT: 399

FM

Fair

Over: NORTH LIZARD CREEK

093331601, Pocahontas, IA

Built 1986 Load: 31.2 t ADT: 399

FM

Fair

Over: DRAIN DITCH NO 96

088292201, Webster, IA

Built 1981 Load: 31.2 t ADT: 50

FM

Fair

Over: BEAVER CREEK

099233508, Winnebago, IA

Built 1987 Load: 31.2 t ADT: 848

E58 75TH ST

Fair

Over: BR BUCKEYE CK

082121103, Benton, IA

Built 1972 Load: 31.3 t ADT: 15

FM

Fair

Over: STEIN CREEK

084121004, Benton, IA

Built 1958 Load: 31.3 t ADT: 10

LOCAL

Fair

Over: ROCK CREEK

082032301, Cedar, IA

Built 1986 Load: 31.3 t ADT: 35

WHEAT AVE

Fair

Over: NORTH WYACONDAH DITCH

067121404, Davis, IA

Built 1999 Load: 31.3 t ADT: 20

WB US 20

Fair

Over: MAQUOKETA RIVER

1.7 mi. E of Jct. IA 13, Delaware, IA

Built 1973 Load: 31.3 t ADT: 3,850

FM

Fair

Over: TIPTON CREEK

087211701, Hardin, IA

Built 1968 Load: 31.3 t ADT: 236

FM 50TH ST

Fair

Over: BEAVER CREEK

100133601, Howard, IA

Built 1970 Load: 31.3 t ADT: 314

DOGWOOD ROAD

Fair

Over: DRAINAGE

075403401, Pottawattamie, IA

Built 1998 Load: 31.3 t ADT: 26

LOCAL

Fair

Over: GRAND RIVER

075300604, Adair, IA

Built 2005 Load: 31.4 t ADT: 5

E TAMA RD

Fair

Over: TRIB TO MILLER CREEK

87-13-34-03-10, Black Hawk, IA

Built 1974 Load: 31.4 t ADT: 314

RICKARD RD

Fair

Over: TRIB TO SPRING CREEK

88-11-34-01-10, Black Hawk, IA

Built 1984 Load: 31.4 t ADT: 44

240TH ST

Fair

Over: STREAM

091111301, Bremer, IA

Built 2018 Load: 31.4 t ADT: 39

FM

Fair

Over: SMALL STREAM

090072307, Buchanan, IA

Built 1970 Load: 31.4 t ADT: 599

FM

Fair

Over: SMALL STREAM

090072403, Buchanan, IA

Built 1970 Load: 31.4 t ADT: 599

FM

Fair

Over: SMALL STREAM

090073104, Buchanan, IA

Built 1968 Load: 31.4 t ADT: 982

LOC KEOKUK AVE

Fair

Over: SMALL STREAM

090090208, Buchanan, IA

Built 1976 Load: 31.4 t ADT: 154

LOCAL

Fair

Over: BRANCH RACCOON RIVER

092351001, Buena Vista, IA

Built 1970 Load: 31.4 t ADT: 45

FM

Fair

Over: PANTHER CREEK

080292301, Dallas, IA

Built 1967 Load: 31.4 t ADT: 170

LOCAL

Fair

Over: KNOTTY CREEK

070031205, Des Moines, IA

Built 1900 Load: 31.4 t ADT: 26

CEDAR CROSS RD

Fair

Over: MIDDLE FORK CATFISH CRK

S. OF CENTER GROVE DR., Dubuque, IA

Built 1985 Load: 31.4 t ADT: 10,390

FM

Fair

Over: SMALL CREEK

085E52904, Jackson, IA

Built 1969 Load: 31.4 t ADT: 70

SPANISH RD

Fair

Over: SOUTH HOOSIER CREEK

082073602, Linn, IA

Built 1987 Load: 31.4 t ADT: 137

US 65

Fair

Over: WHITE BREAST CREEK

0.3 MI. S OF JCT. US 34, Lucas, IA

Built 1992 Load: 31.4 t ADT: 1,260

LOCAL

Fair

Over: MUCHAKINOCK CREEK

074161117, Mahaska, IA

Built 1974 Load: 31.4 t ADT: 80

LOCAL

Fair

Over: CYLINDER CREEK

097313201, Palo Alto, IA

Built 1974 Load: 31.4 t ADT: 35

ROSEWOOD ROAD

Fair

Over: SILVER CREEK

076400401, Pottawattamie, IA

Built 1994 Load: 31.4 t ADT: 15

Showing 6,001-6,050 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.