State profile · Above median Poor share

Iowa bridge safety

Condition ratings, load ratings, and Poor-condition data for every public highway bridge in Iowa, based on the FHWA National Bridge Inventory.

20,753
Public bridges
36.5%
Good condition
20.0%
Poor condition

Data updated May 2026

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 whose lowest applicable component is rated 0-4

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 - Poor-condition share 66.7%
National avg

Lower is better. Bar maxes at 30% (worst-state ceiling). National average sits at 7.0%.

Condition Distribution

Iowa38.5%40.4%21.1%GoodFairPoor
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 by Poor-condition share (lower share = better)

States are ranked by the share of bridges whose lowest applicable component rating is 4 or below. This describes recorded condition; it does not measure funding effectiveness or live crossing safety. States here sit immediately above and below Iowa on the same metric.

WV

West Virginia

16.02% top marginal rate
Structure
Progressive
Burden @ $100K
$7,679

SD

South Dakota

16.24% top marginal rate
Structure
Progressive
Burden @ $100K
$5,905
Selected

IA

Iowa

20.01% top marginal rate
Structure
Progressive
Burden @ $100K
$20,753

VI

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 the portal's composite display score. Inspection intervals are risk-based under current NBIS rules.

270TH STREET

Poor

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

Poor

Over: MUD CREEK

87-12-15-02-10, Black Hawk, IA

Built 1948 Load: 2.7 t ADT: 11

LOCAL - 700TH

Poor

Over: TRIB TROUBLESOME CREEK

077351402, Cass, IA

Built 1983 Load: 2.7 t ADT: 11

LOCAL - DAYTONA

Poor

Over: BUCK CREEK

077361903, Cass, IA

Built 1980 Load: 2.7 t ADT: 35

100TH ST.

Poor

Over: UNION CREEK

083E20101, Clinton, IA

Built 1900 Load: 2.7 t ADT: 78

All Bridges in Iowa

LOCAL

Fair

Over: HONEY CREEK

068331202, Taylor, IA

Built 1972 Load: 18.9 t ADT: 11

340TH

Fair

Over: STREAM

098203602, Worth, IA

Built 1928 Load: 18.9 t ADT: 47

FM

Fair

Over: STREAM

067162101, Appanoose, IA

Built 1960 Load: 19.0 t ADT: 45

LOCAL

Fair

Over: CREEK

079340303, Audubon, IA

Built 1933 Load: 19.0 t ADT: 15

MOLINE RD

Fair

Over: TRIB QUARTER SECTION RUN

90-12-07-02-10, Black Hawk, IA

Built 1956 Load: 19.0 t ADT: 49

LOCAL

Fair

Over: IOWAY CREEK

084250101, Boone, IA

Built 1952 Load: 19.0 t ADT: 100

LOCAL 330TH ST

Fair

Over: WALTON CREEK

087073501, Buchanan, IA

Built 2006 Load: 19.0 t ADT: 41

540TH ST

Fair

Over: STREAM

074370706, Cass, IA

Built 1984 Load: 19.0 t ADT: 50

LOCAL/RICHLAND

Fair

Over: SMALL

075373201, Cass, IA

Built 2008 Load: 19.0 t ADT: 26

APPLE

Fair

Over: WINNEBAGO RIV

097221904, Cerro Gordo, IA

Built 1953 Load: 19.0 t ADT: 41

LOCAL

Fair

Over: PARADISE CREEK

083402701, Crawford, IA

Built 1983 Load: 19.0 t ADT: 30

LOCAL

Fair

Over: WELCH CREEK

083403203, Crawford, IA

Built 1999 Load: 19.0 t ADT: 11

LOC 122 ST

Fair

Over: LINDSEY CREEK

090051603, Delaware, IA

Built 1981 Load: 19.0 t ADT: 20

ROOSTER LN

Fair

Over: SIDE DITCH BRIDGE

0.1 mi. N of IA 32, Dubuque, IA

Built 1965 Load: 19.0 t ADT: 10

LOCAL

Fair

Over: SMALL STREAM

097162102, Floyd, IA

Built 1974 Load: 19.0 t ADT: 20

LOCAL RD

Fair

Over: BRANCH BLACKHAWK CREEK

089163501, Grundy, IA

Built 1971 Load: 19.0 t ADT: 26

2260 305TH ST

Fair

Over: WINNEBAGO RIVER

097232203, Hancock, IA

Built 1974 Load: 19.0 t ADT: 82

FM

Fair

Over: DRAINAGE DITCH

091282301, Humboldt, IA

Built 1900 Load: 19.0 t ADT: 529

LOCAL

Fair

Over: BR MINERVA CREEK

085203202, Marshall, IA

Built 1947 Load: 19.0 t ADT: 16

FA-235TH ST

Fair

Over: WAUBONSIE CREEK

071432508, Mills, IA

Built 1959 Load: 19.0 t ADT: 60

FA-LAMBERT AVE

Fair

Over: RAINES BRANCH

072413203, Mills, IA

Built 1951 Load: 19.0 t ADT: 428

DANCER AVE

Fair

Over: ROCK CREEK

098181502, Mitchell, IA

Built 1925 Load: 19.0 t ADT: 11

LOCAL RD

Fair

Over: INDIAN CREEK

072390501, Montgomery, IA

Built 1971 Load: 19.0 t ADT: 15

FM

Fair

Over: CREEK

100403202, Osceola, IA

Built 1939 Load: 19.0 t ADT: 71

290TH STREET

Fair

Over: LONG BRANCH

067381501, Page, IA

Built 1984 Load: 19.0 t ADT: 29

FM C-44

Fair

Over: SMALL

091452301, Plymouth, IA

Built 1978 Load: 19.0 t ADT: 190

FM K-42

Fair

Over: MINK CREEK

092460304, Plymouth, IA

Built 1961 Load: 19.0 t ADT: 628

FM

Fair

Over: MINK CREEK

093463402, Plymouth, IA

Built 1961 Load: 19.0 t ADT: 628

FM-MAGNOLIA RD

Fair

Over: KEG CREEK

076411901, Pottawattamie, IA

Built 1960 Load: 19.0 t ADT: 477

FM

Fair

Over: STREAM

078150813, Poweshiek, IA

Built 1969 Load: 19.0 t ADT: 2,000

FM

Fair

Over: SMALL STREAM

079142401, Poweshiek, IA

Built 1940 Load: 19.0 t ADT: 20

520TH AVE

Fair

Over: WALNUT CREEK

083242802, Story, IA

Built 1900 Load: 19.0 t ADT: 80

PLEASANT VALLEY

Fair

Over: BEAR CREEK

084230505, Story, IA

Built 1900 Load: 19.0 t ADT: 45

530TH AVE

Fair

Over: KEIGLEY BRANCH

085242202, Story, IA

Built 1917 Load: 19.0 t ADT: 20

LOCAL ROAD

Fair

Over: PAINTER CREEK

075252208, Warren, IA

Built 2006 Load: 19.0 t ADT: 11

LOCAL ROAD

Fair

Over: WEST FORK CROOKED CREEK

075081101, Washington, IA

Built 2008 Load: 19.0 t ADT: 50

LOCAL

Fair

Over: STREAM

089450301, Woodbury, IA

Built 2003 Load: 19.0 t ADT: 11

LOCAL

Fair

Over: DRAINAGE DITCH 14

091242001, Wright, IA

Built 1974 Load: 19.0 t ADT: 81

TRENTON AVE

Fair

Over: STREAM

075302002, Adair, IA

Built 1952 Load: 19.1 t ADT: 72

LOCAL

Fair

Over: WALNUT CREEK

083381704, Crawford, IA

Built 1956 Load: 19.1 t ADT: 11

LOCAL

Fair

Over: BUNCOMBE CREEK

087E21401, Dubuque, IA

Built 1996 Load: 19.1 t ADT: 30

COVINGTON RD

Fair

Over: SILVER CREEK

083081014, Linn, IA

Built 1955 Load: 19.1 t ADT: 5,696

LOCAL

Fair

Over: OTTER CREEK OVERFLOW

098423202, Osceola, IA

Built 1954 Load: 19.1 t ADT: 41

LOCAL RD

Fair

Over: BRANCH FOUR MILE CREEK

081243504, Polk, IA

Built 1975 Load: 19.1 t ADT: 15

210TH ST

Fair

Over: MILFORD 32 DD

084233401, Story, IA

Built 1900 Load: 19.1 t ADT: 34

LOCAL

Fair

Over: CREEK

096070802, Winneshiek, IA

Built 1980 Load: 19.1 t ADT: 78

MIDDLE HESPER RD

Fair

Over: CREEK

100083504, Winneshiek, IA

Built 1900 Load: 19.1 t ADT: 29

FM

Fair

Over: STREAM

077330803, Adair, IA

Built 1970 Load: 19.2 t ADT: 1,564

LOCAL

Fair

Over: LAKE CR

087321701, Calhoun, IA

Built 1964 Load: 19.2 t ADT: 34

NB US 61

Fair

Over: WAPSIPINICON OVERFLOW

2.8 miles S of U.S. 30, Clinton, IA

Built 1981 Load: 19.2 t ADT: 8,800

Showing 2,351-2,400 of 20,753 bridges

Related

All states → | National rankings → | Understanding conditions → | Retired SD term explained →
Data sourced from the FHWA National Bridge Inventory (NBI), latest released cycle. See our methodology for details. Retrieved and formatted by PlainBridges.

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). Poor condition is an inspection-record category, not a closure or unsafe-to-cross designation. Consult the bridge owner for current status.

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.

Every figure on PlainBridge is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.