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 580TH ST

Poor

Over: SMALL CREEK

091422801, Cherokee, IA

Built 1900 Load: 34.0 t ADT: 15

FM

Poor

Over: LITTLE SIOUX RIVER

098371001, Dickinson, IA

Built 1979 Load: 34.1 t ADT: 1,076

FM

Poor

Over: CLEAR CREEK

100053503, Allamakee, IA

Built 1962 Load: 34.3 t ADT: 200

FM

Poor

Over: SMALL STREAM

073030704, Louisa, IA

Built 1972 Load: 34.3 t ADT: 45

FM (LWC)

Poor

Over: SMALL STREAM

086100702, Benton, IA

Built 1990 Load: 34.4 t ADT: 330

ANSBOROUGH AVE

Poor

Over: TRIB TO MILLER CREEK

87-13-28-02-10, Black Hawk, IA

Built 1978 Load: 34.5 t ADT: 11

450TH

Poor

Over: STREAM

099201201, Worth, IA

Built 1962 Load: 34.5 t ADT: 34

380 AVENUE

Poor

Over: MILL CREEK

067400802, Fremont, IA

Built 1973 Load: 34.6 t ADT: 40

430TH STREET

Poor

Over: STREAM

076391704, Pottawattamie, IA

Built 1940 Load: 34.6 t ADT: 26

FM

Poor

Over: STREAM

071311601, Union, IA

Built 1951 Load: 34.6 t ADT: 40

S. 18TH AVE

Poor

Over: OVER UP RR

084173100, Marshall, IA

Built 1980 Load: 34.7 t ADT: 6,813

LCL-305TH ST

Poor

Over: CREEK

072411804, Mills, IA

Built 1990 Load: 34.7 t ADT: 11

LOCAL

Poor

Over: SMALL

094471302, Sioux, IA

Built 1978 Load: 34.7 t ADT: 34

LOCAL

Poor

Over: STREAM

078131204, Poweshiek, IA

Built 1965 Load: 34.8 t ADT: 30

LOCAL

Poor

Over: STREAM

081162601, Poweshiek, IA

Built 1953 Load: 34.8 t ADT: 30

LOCAL ROAD

Poor

Over: CREEK

097081903, Winneshiek, IA

Built 1977 Load: 34.8 t ADT: 59

FM

Poor

Over: CAIN CREEK

088340301, Calhoun, IA

Built 1968 Load: 34.9 t ADT: 110

LOCAL - 580TH

Poor

Over: LITTLE CAMP CREEK

077371102, Cass, IA

Built 1981 Load: 35.0 t ADT: 5

150TH ST

Poor

Over: BROKEN KETTLE CREEK

093473601, Plymouth, IA

Built 1952 Load: 35.0 t ADT: 26

LOCAL

Poor

Over: N SKUNK RIVER

083202002, Marshall, IA

Built 1917 Load: 35.1 t ADT: 49

FM

Poor

Over: CREEK

084172502, Marshall, IA

Built 1917 Load: 35.1 t ADT: 108

LOCAL

Poor

Over: MINERVA CR

084201002, Marshall, IA

Built 1917 Load: 35.1 t ADT: 21

FM

Poor

Over: WALNUT CREEK

080E11208, Scott, IA

Built 1949 Load: 35.1 t ADT: 1,060

FM

Poor

Over: CRANE CREEK

096113004, Chickasaw, IA

Built 1971 Load: 35.3 t ADT: 275

SAWYER RD

Poor

Over: TRIB TO BUFFALO CREEK

085050407, Linn, IA

Built 1926 Load: 35.3 t ADT: 1,100

LOCAL

Poor

Over: PLEASANT CREEK

077142705, Mahaska, IA

Built 1949 Load: 35.3 t ADT: 15

FM

Poor

Over: STREAM

068263605, Decatur, IA

Built 1940 Load: 35.5 t ADT: 60

LOCAL

Poor

Over: BEAVER CREEK

083281101, Boone, IA

Built 1920 Load: 35.6 t ADT: 26

LOCAL

Poor

Over: HICKORY CREEK

074201202, Marion, IA

Built 1997 Load: 35.6 t ADT: 15

WALNUT ST

Poor

Over: ABANDON RR

082200903, Marshall, IA

Built 1977 Load: 35.6 t ADT: 689

LOCAL

Poor

Over: BRANCH IOWA RIVER

082140603, Tama, IA

Built 1983 Load: 35.6 t ADT: 11

FM

Poor

Over: WEST 102 RIVER

070352401, Taylor, IA

Built 1985 Load: 35.6 t ADT: 309

LOCAL

Poor

Over: CREEK

086192703, Hardin, IA

Built 1995 Load: 35.7 t ADT: 11

LINCOLN AVE

Poor

Over: BR CRANE CREEK

098133606, Howard, IA

Built 1990 Load: 35.7 t ADT: 25

LOCAL

Poor

Over: DEER CREEK

090292204, Webster, IA

Built 1925 Load: 35.7 t ADT: 81

LOCAL

Poor

Over: BR PRAIRIE CK

082110502, Benton, IA

Built 1958 Load: 35.9 t ADT: 25

FM-H AVE.

Poor

Over: WILLOW CREEK

092412902, Cherokee, IA

Built 1924 Load: 35.9 t ADT: 199

FM

Poor

Over: SKUNK RIVER

086243603, Hamilton, IA

Built 1992 Load: 35.9 t ADT: 459

LOCAL

Poor

Over: SMALL STREAM

080211304, Jasper, IA

Built 1925 Load: 35.9 t ADT: 35

308TH AVE.

Poor

Over: SUGAR CREEK

083E40404, Clinton, IA

Built 1985 Load: 36.0 t ADT: 70

S67 WREN AVE

Poor

Over: STREAM

091193502, Franklin, IA

Built 1962 Load: 36.0 t ADT: 79

OLD IA 77

Poor

Over: RICHLAND CREEK

074102210, Keokuk, IA

Built 1932 Load: 36.1 t ADT: 620

LOCAL

Poor

Over: E FK GRAND RIVER

070291301, Ringgold, IA

Built 1940 Load: 36.2 t ADT: 5

LOCAL

Poor

Over: SMALL STREAM

089090402, Buchanan, IA

Built 1951 Load: 36.3 t ADT: 30

FM

Poor

Over: BEAVER CREEK

089172201, Grundy, IA

Built 1973 Load: 36.3 t ADT: 501

FM

Poor

Over: EAST FORK CROOKED CREEK

073050904, Henry, IA

Built 1970 Load: 36.3 t ADT: 910

FM

Poor

Over: W FK GRAND RIVER

070303203, Ringgold, IA

Built 1979 Load: 36.3 t ADT: 190

FM

Poor

Over: BOYER RIVER

088373301, Sac, IA

Built 1979 Load: 36.3 t ADT: 100

FM

Poor

Over: HINKLE CREEK

085112804, Benton, IA

Built 1988 Load: 36.4 t ADT: 530

FM

Poor

Over: TRIB. OF SQUAW CREEK

085253601, Boone, IA

Built 1920 Load: 36.6 t ADT: 90

Showing 19,201-19,250 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.