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

Poor

Over: BLUFF CREEK

074172706, Mahaska, IA

Built 1973 ADT: 11

LOCAL

Poor

Over: S COAL CREEK

074173003, Mahaska, IA

Built 1957 ADT: 15

LOCAL

Poor

Over: DRAINAGE DITCH #2

075163306, Mahaska, IA

Built 1900 ADT: 11

FM

Poor

Over: N SKUNK RIVER

076141001, Mahaska, IA

Built 1966 ADT: 370

FM

Poor

Over: N SKUNK RIVER OVERFLOW

076141001, Mahaska, IA

Built 1961 ADT: 370

LOCAL

Poor

Over: DRAINAGE

076150501, Mahaska, IA

Built 1950 ADT: 80

LOCAL

Poor

Over: MITCHELL CREEK

076161603, Mahaska, IA

Built 1936 ADT: 26

LOCAL

Poor

Over: PAINTER CREEK

076163507, Mahaska, IA

Built 1951 ADT: 90

140TH ST

Poor

Over: CEDAR CREEK

077142505, Mahaska, IA

Built 1950 ADT: 10

FM

Poor

Over: DRAINAGE

077153203, Mahaska, IA

Built 1954 ADT: 30

FIELD ENTRANCE

Poor

Over: MUCHAKINOCK CREEK(SDB)

074162403, Mahaska, IA

Built 1952 ADT: 10

FM

Poor

Over: BNSF RR AND STREAM

075190306, Marion, IA

Built 1964 ADT: 2,620

94TH PLACE

Poor

Over: TRACEY CREEK

075202804, Marion, IA

Built 1958 ADT: 40

FM

Poor

Over: SOUTH TIMBER CREEK

082180902, Marshall, IA

Built 1957 ADT: 39

FM

Poor

Over: SOUTH TIMBER CREEK

083172801, Marshall, IA

Built 1954 ADT: 59

LOCAL

Poor

Over: BURNETT CR

084170402, Marshall, IA

Built 1917 ADT: 5

LOCAL

Poor

Over: BR BURNETT CR

085173101, Marshall, IA

Built 1977 ADT: 5

LOCAL

Poor

Over: DOWD CREEK

085190103, Marshall, IA

Built 1916 ADT: 16

FM

Poor

Over: CREEK

085190602, Marshall, IA

Built 1918 ADT: 25

LOCAL

Poor

Over: BR MINERVA CR

085200502, Marshall, IA

Built 1919 ADT: 30

LCL-JAHNKE AVE

Poor

Over: SILVER CREEK

072411903, Mills, IA

Built 1938 ADT: 5

LCL-COMPASS AVE

Poor

Over: FARM CREEK

073401407, Mills, IA

Built 1963 ADT: 5

PRIMROSE AVE

Poor

Over: CREEK

100161604, Mitchell, IA

Built 1950 ADT: 20

PRIMROSE AVE

Poor

Over: LITTLE CEDAR RIVER

099161604, Mitchell, IA

Built 1908 ADT: 33

LOCAL

Poor

Over: WILLOW CREEK

082421404, Monona, IA

Built 1905 ADT: 11

LOCAL

Poor

Over: JORDAN CREEK

082430503, Monona, IA

Built 1912 ADT: 15

LOCAL ROAD

Poor

Over: LOCAL STREAM

085431405, Monona, IA

Built 1964 ADT: 26

LOCAL RD

Poor

Over: WEST FORK DD

085450401, Monona, IA

Built 1912 ADT: 34

100TH ST

Poor

Over: FARMERS GARRETSON DD

085450501, Monona, IA

Built 1913 ADT: 11

SOUTH CLINTON ST

Poor

Over: OVER BNSF RR

072172206, Monroe, IA

Built 1932 ADT: 1,585

LOCAL

Poor

Over: DRAINAGE

071171904, Monroe, IA

Built 1954 ADT: 20

LOCAL

Poor

Over: DRAINAGE

071172907, Monroe, IA

Built 1943 ADT: 40

FM

Poor

Over: LITTLE TARKIO TRIB

071370702, Montgomery, IA

Built 1947 ADT: 60

FM

Poor

Over: NISHNABOTNA

071381901, Montgomery, IA

Built 1942 ADT: 60

LOCAL

Poor

Over: WALNUT CREEK

071390401, Montgomery, IA

Built 1966 ADT: 11

LOCAL ROAD

Poor

Over: WALNUT CREEK

071391701, Montgomery, IA

Built 1951 ADT: 20

LOCAL

Poor

Over: LOCAL CREEK

071392902, Montgomery, IA

Built 1940 ADT: 11

LOCAL

Poor

Over: LITTLE TARKIO CREEK

072371401, Montgomery, IA

Built 1979 ADT: 29

LOCAL

Poor

Over: DRAINAGE

072372602, Montgomery, IA

Built 1942 ADT: 20

FM

Poor

Over: NISHNABOTNA TRIB

072380303, Montgomery, IA

Built 1949 ADT: 29

LOCAL ROAD

Poor

Over: LOCAL CREEK

072381702, Montgomery, IA

Built 1963 ADT: 112

LOCAL RD

Poor

Over: LITTLE TARKIO CREEK

072383605, Montgomery, IA

Built 1950 ADT: 11

LOCAL ROAD

Poor

Over: MINOR DRAINAGE

072393301, Montgomery, IA

Built 1930 ADT: 61

LOCAL ROAD

Poor

Over: MINOR DRAINAGE

073360104, Montgomery, IA

Built 1971 ADT: 20

LOCAL RD

Poor

Over: W NODAWAY RIVER

073361603, Montgomery, IA

Built 1970 ADT: 26

LOCAL

Poor

Over: BRANCH TARKIO CREEK

073372802, Montgomery, IA

Built 1961 ADT: 26

LOCAL

Poor

Over: BR WALNUT CREEK

073380502, Montgomery, IA

Built 1988 ADT: 11

LOCAL

Poor

Over: CREEK

077012704, Muscatine, IA

Built 1956 ADT: 35

LOCAL

Poor

Over: LOWE RUN

077023205, Muscatine, IA

Built 1928 ADT: 380

FM

Poor

Over: WEST BRANCH MUD CREEK

078E11601, Muscatine, IA

Built 1960 ADT: 80

Showing 16,901-16,950 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.