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

E 116TH ST S

Poor

Over: SMALL STREAM

079172902, Jasper, IA

Built 1926 Load: 12.3 t ADT: 16

S 12TH AVE W

Poor

Over: SMALL STREAM

079210601, Jasper, IA

Built 1926 Load: 12.3 t ADT: 150

LOCAL

Poor

Over: CLEAR CREEK

083203101, Marshall, IA

Built 1941 Load: 12.3 t ADT: 26

LOCAL

Poor

Over: CREEK

091382801, Buena Vista, IA

Built 1976 Load: 12.4 t ADT: 45

FM-PADDOCK RD

Poor

Over: LOCAL CREEK

071432103, Mills, IA

Built 1970 Load: 12.4 t ADT: 71

SEC RD

Poor

Over: WATERMAN CR

094390303, O'Brien, IA

Built 1915 Load: 12.4 t

FM

Poor

Over: CLOVERDALE CREEK

099412902, Osceola, IA

Built 1958 Load: 12.4 t ADT: 459

LOCAL

Poor

Over: LITTLE BEAR CREEK

080143004, Poweshiek, IA

Built 1952 Load: 12.4 t ADT: 20

LOCAL

Poor

Over: NO NAME CREEK

086370602, Sac, IA

Built 1926 Load: 12.4 t ADT: 34

LOCAL

Poor

Over: BR RACCOON RIVER

091361702, Buena Vista, IA

Built 1977 Load: 12.5 t ADT: 15

LOCAL - 660TH

Poor

Over: STREAM

074353104, Cass, IA

Built 1981 Load: 12.5 t ADT: 5

INDIAN AVE

Poor

Over: W ROCK CR

081030402, Cedar, IA

Built 1918 Load: 12.5 t ADT: 11

HOWARD AVE

Poor

Over: CRANE CREEK

098130504, Howard, IA

Built 1920 Load: 12.5 t ADT: 63

LOCAL

Poor

Over: DD

093293101, Humboldt, IA

Built 1900 Load: 12.5 t ADT: 11

FM

Poor

Over: OLIVE BRANCH CREEK

074140103, Mahaska, IA

Built 1950 Load: 12.5 t ADT: 30

LOCAL

Poor

Over: N LIZARD CREEK

093330701, Pocahontas, IA

Built 1916 Load: 12.5 t ADT: 5

240TH STREET

Poor

Over: WEST FORK 102 RIVER

071341301, Adams, IA

Built 1974 Load: 12.6 t ADT: 34

4TH STREET

Poor

Over: STREAM

071340307, Adams, IA

Built 1925 Load: 12.6 t ADT: 120

FM

Poor

Over: BLUFF CREEK

085273101, Boone, IA

Built 1915 Load: 12.6 t ADT: 50

150TH ST

Poor

Over: BR ROCK CR

082033503, Cedar, IA

Built 1920 Load: 12.6 t ADT: 15

QUAIL

Poor

Over: BEAVER DAM CREEK

094203504, Cerro Gordo, IA

Built 1913 Load: 12.6 t ADT: 15

LOCAL

Poor

Over: ROCKY RUN

084383303, Crawford, IA

Built 1946 Load: 12.6 t ADT: 72

FM

Poor

Over: STREAM

071181303, Monroe, IA

Built 1942 Load: 12.6 t ADT: 80

NOBLE AVE

Poor

Over: DEEP CREEK

093443104, Plymouth, IA

Built 1953 Load: 12.6 t ADT: 30

LOCAL

Poor

Over: SMALL STREAM

079382701, Shelby, IA

Built 1950 Load: 12.6 t ADT: 11

LOCAL-630TH ST

Poor

Over: N PIERSON CREEK

090422201, Cherokee, IA

Built 1920 Load: 12.7 t ADT: 20

LOCAL

Poor

Over: LITTLE TURKEY RIVER

096111402, Chickasaw, IA

Built 1966 Load: 12.7 t ADT: 62

250TH AVE

Poor

Over: STREAM

67251002, Decatur, IA

Built 1972 Load: 12.7 t ADT: 5

LOCAL

Poor

Over: LITTLE FLINT CREEK

071043502, Des Moines, IA

Built 1920 Load: 12.7 t ADT: 113

LOCAL

Poor

Over: CLEAR WATER CREEK

094183104, Floyd, IA

Built 1927 Load: 12.7 t ADT: 33

CHESTNUT AVENUE

Poor

Over: EAST NODAWAY RIVER

071351502, Adams, IA

Built 1930 Load: 12.8 t ADT: 26

LOCAL

Poor

Over: BIG CEDAR RIVER

071092810, Jefferson, IA

Built 1991 Load: 12.8 t ADT: 34

LOCAL

Poor

Over: STREAM

067291304, Ringgold, IA

Built 1953 Load: 12.8 t ADT: 5

LOCAL

Poor

Over: STREAM

071280205, Union, IA

Built 1991 Load: 12.8 t ADT: 35

LOCAL

Poor

Over: NODAWAY RIVER, BRANCH

074331202, Adair, IA

Built 1960 Load: 12.9 t ADT: 35

NOTCHWOOD AVE

Poor

Over: KEMP CREEK

073332804, Adams, IA

Built 1960 Load: 12.9 t ADT: 20

LOCAL

Poor

Over: PRAIRIE CREEK

086340201, Calhoun, IA

Built 1980 Load: 12.9 t ADT: 30

LOCAL

Poor

Over: MIDDLE RACOON RIVER

083342703, Carroll, IA

Built 1900 Load: 12.9 t ADT: 34

HENNEPIN RD

Poor

Over: ELK CREEK

091040208, Clayton, IA

Built 1920 Load: 12.9 t ADT: 25

280TH ST

Poor

Over: MOSQUITO CREEK

078410301, Harrison, IA

Built 1940 Load: 12.9 t ADT: 20

LOCAL RD

Poor

Over: TOM CREEK

077292502, Madison, IA

Built 1930 Load: 12.9 t ADT: 26

LOCAL

Poor

Over: STREAM

089370201, Sac, IA

Built 1924 Load: 12.9 t ADT: 30

FM 260TH ST

Poor

Over: QUARTER SEC RUN

091132005, Bremer, IA

Built 1939 Load: 13.0 t ADT: 275

FM

Poor

Over: ELK CREEK

068271202, Decatur, IA

Built 1900 Load: 13.0 t ADT: 40

LOCAL

Poor

Over: SMALL CREEK

084E61103, Jackson, IA

Built 1920 Load: 13.0 t ADT: 20

290TH ST

Poor

Over: DRAINAGE DITCH #2

074160907, Mahaska, IA

Built 1900 Load: 13.0 t ADT: 45

LOCAL

Poor

Over: SOUTH TIMBER CREEK

082180104, Marshall, IA

Built 1939 Load: 13.0 t ADT: 16

280TH ST

Poor

Over: MUD CREEK

090440601, Plymouth, IA

Built 1900 Load: 13.0 t ADT: 26

FM

Poor

Over: BIG CEDAR CK DD #41

093341502, Pocahontas, IA

Built 1969 Load: 13.0 t ADT: 379

LOCAL

Poor

Over: E BIG CREEK

067282401, Ringgold, IA

Built 1958 Load: 13.0 t ADT: 5

Showing 17,001-17,050 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.