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

LINN BUCHANAN

Fair

Over: DEAD DOG RUN

086070303, Linn, IA

Built 1949 Load: 27.5 t ADT: 44

NB I-380

Fair

Over: CC RR

2.6 MI. S OF JCT. 100, Linn, IA

Built 1980 Load: 27.5 t ADT: 38,800

DUBUQUE ST

Fair

Over: STREAM

077192501, Marion, IA

Built 1968 Load: 27.5 t ADT: 41

IA 175

Fair

Over: DRAINAGE DITCH

4.5 mi. E of E jct SR L20, Monona, IA

Built 1973 Load: 27.5 t ADT: 1,200

IA 404 SB

Fair

Over: FLOYD RIVER

0.4 mi. N of jct. IA 3, Plymouth, IA

Built 1957 Load: 27.5 t ADT: 2,410

FM

Fair

Over: STREAM

078130504, Poweshiek, IA

Built 1956 Load: 27.5 t ADT: 30

LOCAL

Fair

Over: WEST BRANCH

095452702, Sioux, IA

Built 1950 Load: 27.5 t ADT: 100

LOCAL

Fair

Over: TWELVE MILE CREEK

086151701, Tama, IA

Built 1950 Load: 27.5 t ADT: 20

CO RD W64

Fair

Over: DRAINAGE DITCH

074062206, Washington, IA

Built 1982 Load: 27.5 t ADT: 210

WB US 20

Fair

Over: DES MOINES RIVER

2.6 mi. E of US 169, Webster, IA

Built 1990 Load: 27.5 t ADT: 4,300

OAKLAND AVE

Fair

Over: STREAM

091121602, Bremer, IA

Built 1994 Load: 27.6 t ADT: 20

270TH ST

Fair

Over: STREAM

091123501, Bremer, IA

Built 1994 Load: 27.6 t ADT: 148

B-14

Fair

Over: PRIVATE DR

097240203, Hancock, IA

Built 1972 Load: 27.6 t ADT: 3,502

FM & 220TH ST

Fair

Over: PIGEON CREEK

079410101, Harrison, IA

Built 1952 Load: 27.6 t ADT: 26

UTAH AVE

Fair

Over: STREAM

077052906, Johnson, IA

Built 1994 Load: 27.6 t ADT: 70

LOCAL

Fair

Over: LITTLE ROCK RIVER

098430604, Lyon, IA

Built 1982 Load: 27.6 t ADT: 143

FM

Fair

Over: TOOLE CREEK

100461902, Lyon, IA

Built 1970 Load: 27.6 t ADT: 290

160TH STREET

Fair

Over: W TARKIO RIVER

069380301, Page, IA

Built 2002 Load: 27.6 t ADT: 29

FM

Fair

Over: SO BRANCH SALT CREEK

084141904, Tama, IA

Built 1953 Load: 27.6 t ADT: 39

POWER PLANT RD

Fair

Over: BNSF RR

073152604, Wapello, IA

Built 1981 Load: 27.6 t ADT: 470

IA 2

Fair

Over: STREAM

1.7 MI. E OF IA 14, Wayne, IA

Built 1962 Load: 27.6 t ADT: 2,920

EB US 20

Fair

Over: DES MOINES RIVER

2.6 MI. E OF JCT. US 169, Webster, IA

Built 1990 Load: 27.6 t ADT: 4,300

LOCAL ROAD

Fair

Over: TURKEY RIVER

098101701, Winneshiek, IA

Built 1964 Load: 27.6 t ADT: 44

LOCAL

Fair

Over: STREAM

088432105, Woodbury, IA

Built 2004 Load: 27.6 t ADT: 34

IA 9

Fair

Over: SHELL ROCK RIVER

0.1 mi. E of W Jct. S56, Worth, IA

Built 1921 Load: 27.6 t ADT: 2,160

QUINCE AVENUE

Fair

Over: WILLOW CREEK

071332402, Adams, IA

Built 1965 Load: 27.7 t ADT: 20

ORANGE AVENUE

Fair

Over: WILLOW CREEK

071332702, Adams, IA

Built 1969 Load: 27.7 t ADT: 50

LOCAL

Fair

Over: LITTLE BEAVER CREEK

082271802, Boone, IA

Built 1900 Load: 27.7 t ADT: 26

330TH ST

Fair

Over: E BR WAPSINONOC CREEK

079033201, Cedar, IA

Built 1996 Load: 27.7 t ADT: 35

US 18

Fair

Over: LITTLE SIOUX OVERFLOW

3.6 mi. E of E jct. US 71, Clay, IA

Built 1931 Load: 27.7 t ADT: 4,170

180TH AVE

Fair

Over: PRAIRIE CREEK

095370402, Clay, IA

Built 2008 Load: 27.7 t ADT: 21

2ND ST

Fair

Over: BOONE RIVER

000000000, Hamilton, IA

Built 1950 Load: 27.7 t ADT: 3,797

LOCAL

Fair

Over: DRAINAGE DITCH

091273602, Humboldt, IA

Built 1941 Load: 27.7 t ADT: 80

FM-390TH ST

Fair

Over: INDIAN CREEK

072402204, Mills, IA

Built 1936 Load: 27.7 t ADT: 89

US 59

Fair

Over: MILL CREEK

4.2 mi. N of N Jct IA 10, O'Brien, IA

Built 1973 Load: 27.7 t ADT: 940

FM

Fair

Over: BEAVER CREEK

080251708, Polk, IA

Built 1972 Load: 27.7 t ADT: 1,524

460TH ST

Fair

Over: JORDAN CREEK

075393404, Pottawattamie, IA

Built 2013 Load: 27.7 t ADT: 11

FM

Fair

Over: STREAM

067282801, Ringgold, IA

Built 1955 Load: 27.7 t ADT: 5

LOCAL

Fair

Over: SALT CREEK

083131502, Tama, IA

Built 1995 Load: 27.7 t ADT: 26

123RD ST

Fair

Over: TURKEY RIVER

096092103, Winneshiek, IA

Built 1936 Load: 27.7 t ADT: 118

IA 3

Fair

Over: STREAM

1.2 mi. W of jct. US 71, Buena Vista, IA

Built 1957 Load: 27.8 t ADT: 1,470

LOCAL

Fair

Over: KILSON CREEK

091171005, Butler, IA

Built 1997 Load: 27.8 t ADT: 44

LOCAL

Fair

Over: SMALL STREAM

091183502, Butler, IA

Built 1900 Load: 27.8 t ADT: 16

FM

Fair

Over: WEST NISHNABOTNA RIVER

083361502, Carroll, IA

Built 1977 Load: 27.8 t ADT: 847

MONROE AVE

Fair

Over: CROOKED CREEK

080023005, Cedar, IA

Built 1975 Load: 27.8 t ADT: 34

IA 136

Fair

Over: ELWOOD CREEK

3.1 MI. N OF JCT. US 61, Clinton, IA

Built 1952 Load: 27.8 t ADT: 1,000

135TH ST.

Fair

Over: ELK RIVER

083E72003, Clinton, IA

Built 1986 Load: 27.8 t ADT: 41

LOCAL

Fair

Over: KILGORE CREEK

068251003, Decatur, IA

Built 1994 Load: 27.8 t ADT: 5

IA 3

Fair

Over: LINDSEY CREEK

1.3 MI. E OF E Jct. IA 13, Delaware, IA

Built 1979 Load: 27.8 t ADT: 2,070

LOC 215TH ST

Fair

Over: STREAM

089063105, Delaware, IA

Built 1940 Load: 27.8 t ADT: 39

Showing 4,901-4,950 of 20,753 bridges

Related

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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.