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

Fair

Over: STREAM

075181308, Marion, IA

Built 1976 Load: 21.8 t ADT: 16

325TH

Fair

Over: ROCK CREEK

097170703, Mitchell, IA

Built 1956 Load: 21.8 t ADT: 44

FM

Fair

Over: PINE CREEK

077E11708, Muscatine, IA

Built 1949 Load: 21.8 t ADT: 60

113TH ST (FLD)

Fair

Over: ROAD DITCH

085211003, Story, IA

Built 1900 Load: 21.8 t ADT: 10

630TH AVE

Fair

Over: EAST BR INDIAN CREEK

085220502, Story, IA

Built 1955 Load: 21.8 t ADT: 11

LOCAL

Fair

Over: CREEK

075331504, Adair, IA

Built 2008 Load: 21.9 t ADT: 11

JAY AVE

Fair

Over: CREEK

078351601, Audubon, IA

Built 1925 Load: 21.9 t ADT: 35

JUBILEE RD

Fair

Over: SPRING CREEK

87-11-02-03-10, Black Hawk, IA

Built 1951 Load: 21.9 t ADT: 69

US 30 WB

Fair

Over: DES MOINES RIVER

1.3 MILES E OF JCT SR R18, Boone, IA

Built 1963 Load: 21.9 t ADT: 4,400

LOCAL

Fair

Over: BEAVER CREEK

084283201, Boone, IA

Built 1916 Load: 21.9 t ADT: 40

FM

Fair

Over: BLUFF CREEK

085272901, Boone, IA

Built 1900 Load: 21.9 t ADT: 60

180TH ST

Fair

Over: QUARTER SECTION RUN

092131601, Bremer, IA

Built 1993 Load: 21.9 t ADT: 59

LOCAL 170TH

Fair

Over: SMALL STREAM

092140701, Bremer, IA

Built 1997 Load: 21.9 t ADT: 59

LOCAL

Fair

Over: BR RACCOON RIVER

092362802, Buena Vista, IA

Built 1969 Load: 21.9 t ADT: 11

LOCAL

Fair

Over: D.D. NO 20

086320901, Calhoun, IA

Built 1972 Load: 21.9 t ADT: 34

250TH

Fair

Over: CRANE CR

096212203, Cerro Gordo, IA

Built 1941 Load: 21.9 t ADT: 30

LOCAL

Fair

Over: S WHITE BREAST CR

071252201, Clarke, IA

Built 1985 Load: 21.9 t ADT: 11

COUNTY ROAD

Fair

Over: LITTLE BEAVER CREEK

081271104, Dallas, IA

Built 1956 Load: 21.9 t ADT: 41

FM 332 AVE

Fair

Over: BEAR CREEK

089032504, Delaware, IA

Built 1997 Load: 21.9 t ADT: 1,218

LOCAL

Fair

Over: BROWN CREEK

100333203, Emmet, IA

Built 1978 Load: 21.9 t ADT: 40

LOCAL RD

Fair

Over: BRANCH BLACKHAWK CREEK

089162501, Grundy, IA

Built 1966 Load: 21.9 t ADT: 33

LOCAL VIENNA AV

Fair

Over: SPRING CREEK

079412402, Harrison, IA

Built 1960 Load: 21.9 t ADT: 29

LOCAL MARCH AVE

Fair

Over: BRANCH TURKEY CREEK

099123102, Howard, IA

Built 1990 Load: 21.9 t ADT: 15

S 76TH AVE W

Fair

Over: SMALL STREAM

078200203, Jasper, IA

Built 1996 Load: 21.9 t ADT: 30

LOC 30TH AVE

Fair

Over: TRULNER CREEK

094302802, Kossuth, IA

Built 1979 Load: 21.9 t ADT: 11

LOCAL

Fair

Over: STREAM

075182104, Marion, IA

Built 2004 Load: 21.9 t ADT: 466

LOCAL

Fair

Over: CREEK

077E10906, Muscatine, IA

Built 1958 Load: 21.9 t ADT: 80

LOCAL RD

Fair

Over: BRANCH OF BIG CREEK

081250302, Polk, IA

Built 1975 Load: 21.9 t ADT: 71

AURORA AVE

Fair

Over: N WALNUT CREEK

O38090555, Polk, IA

Built 1991 Load: 21.9 t ADT: 1,821

WACO LANE

Fair

Over: NEOLA CREEK

077421204, Pottawattamie, IA

Built 1989 Load: 21.9 t ADT: 5

SUMAC ROAD

Fair

Over: STREAM

077423503, Pottawattamie, IA

Built 1973 Load: 21.9 t ADT: 71

LOCAL

Fair

Over: SMALL STREAM

088380602, Sac, IA

Built 1919 Load: 21.9 t ADT: 26

300TH ST

Fair

Over: CREEK

080E41601, Scott, IA

Built 1970 Load: 21.9 t ADT: 1,390

TELEGRAPH RD

Fair

Over: BLACKHAWK CR

078022591, Scott, IA

Built 1900 Load: 21.9 t ADT: 899

FM

Fair

Over: TWELVE MILE CREEK

072293403, Union, IA

Built 1956 Load: 21.9 t ADT: 128

FM

Fair

Over: STREAM

070103203, Van Buren, IA

Built 1940 Load: 21.9 t ADT: 50

FM

Fair

Over: DES MOINES RIVER

068090222, Van Buren, IA

Built 1985 Load: 21.9 t ADT: 430

LOCAL

Fair

Over: STREAM

069221206, Wayne, IA

Built 1987 Load: 21.9 t ADT: 90

SCENIC RIVER RD

Fair

Over: CREEK

099092607, Winneshiek, IA

Built 1990 Load: 21.9 t ADT: 26

FM

Fair

Over: SHANGHAR CREEK

074322301, Adair, IA

Built 1977 Load: 22.0 t ADT: 468

LOCAL

Fair

Over: CREEK

079343204, Audubon, IA

Built 1939 Load: 22.0 t ADT: 15

IA 210

Fair

Over: BIG CREEK

3.3 MILES E OF JCT IA 17, Boone, IA

Built 1937 Load: 22.0 t ADT: 2,230

GLACIER RD

Fair

Over: DOE CR

092043106, Clayton, IA

Built 1958 Load: 22.0 t ADT: 108

LOCAL 320 ST

Fair

Over: SMALL STREAM

087043001, Delaware, IA

Built 1993 Load: 22.0 t ADT: 26

250TH ST

Fair

Over: SMALL STREAM

088042203, Delaware, IA

Built 1991 Load: 22.0 t ADT: 70

FM 240 ST

Fair

Over: STREAM

088051801, Delaware, IA

Built 1965 Load: 22.0 t ADT: 69

FM 240 ST

Fair

Over: SMALL STREAM

088051803, Delaware, IA

Built 1965 Load: 22.0 t ADT: 79

LOCAL 255 ST

Fair

Over: SMALL STREAM

088051905, Delaware, IA

Built 1968 Load: 22.0 t ADT: 79

LOCAL 190 ST

Fair

Over: STREAM

089031901, Delaware, IA

Built 1969 Load: 22.0 t ADT: 29

LOCAL 280 AVE

Fair

Over: PLUM CREEK

089033002, Delaware, IA

Built 1974 Load: 22.0 t ADT: 39

Showing 3,101-3,150 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.