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

FM

Poor

Over: GRITTER CREEK

078123602, Iowa, IA

Built 1970 Load: 18.0 t ADT: 15

LOCAL

Poor

Over: SMALL STREAM

081180401, Jasper, IA

Built 1952 Load: 18.0 t ADT: 16

100TH AVE

Poor

Over: MOUSE CREEK

073233002, Lucas, IA

Built 1975 Load: 18.0 t ADT: 11

LOCAL ROAD

Poor

Over: OVERFLOW

098472601, Lyon, IA

Built 1900 Load: 18.0 t ADT: 21

LOCAL RD

Poor

Over: W BR GRAND RIVER

074293005, Madison, IA

Built 1951 Load: 18.0 t ADT: 20

FM

Poor

Over: HOWERDON CREEK

076283002, Madison, IA

Built 1954 Load: 18.0 t ADT: 477

LOCAL

Poor

Over: MUCHAKINOCH CREEK

075160703, Mahaska, IA

Built 1951 Load: 18.0 t ADT: 50

PARKER AVE

Poor

Over: SOUTH TIMBER CREEK

082181004, Marshall, IA

Built 1950 Load: 18.0 t ADT: 21

LOCAL

Poor

Over: NORTH TIMBER CREEK

083191902, Marshall, IA

Built 1951 Load: 18.0 t ADT: 30

LOCAL

Poor

Over: NORTH TIMBER CREEK

083192102, Marshall, IA

Built 1950 Load: 18.0 t ADT: 5

LOCAL

Poor

Over: MINERVA CR

084190602, Marshall, IA

Built 1946 Load: 18.0 t ADT: 30

FM

Poor

Over: STREAM

073170803, Monroe, IA

Built 1951 Load: 18.0 t ADT: 70

LOCAL

Poor

Over: DD 98

094331401, Palo Alto, IA

Built 1972 Load: 18.0 t ADT: 21

MARBLE AVE.

Poor

Over: PLYMOUTH CREEK

092453502, Plymouth, IA

Built 1946 Load: 18.0 t ADT: 5

LOCAL

Poor

Over: E FORK GRAND RIVER

070291201, Ringgold, IA

Built 1969 Load: 18.0 t ADT: 5

FM

Poor

Over: W FORK GRAND RIVER

070302101, Ringgold, IA

Built 1950 Load: 18.0 t ADT: 60

FM

Poor

Over: BOYER RIVER

086372806, Sac, IA

Built 1958 Load: 18.0 t ADT: 60

FM

Poor

Over: OUTLET GREEN VALLEY LK

073312601, Union, IA

Built 1951 Load: 18.0 t ADT: 159

LOCAL

Poor

Over: TRIB OF DES MOINES RIVER

068083508, Van Buren, IA

Built 1954 Load: 18.0 t ADT: 62

LOCAL

Poor

Over: SM STREAM

077090103, Washington, IA

Built 1974 Load: 18.0 t ADT: 40

LOCAL

Poor

Over: UPPER IOWA RIVER

098070906, Winneshiek, IA

Built 1900 Load: 18.0 t ADT: 70

POPLAR AVENUE

Poor

Over: STREAM

073332602, Adams, IA

Built 1983 Load: 18.1 t ADT: 29

WELLMAN RD

Poor

Over: TRIB TO SPRING CREEK

87-11-10-01-10, Black Hawk, IA

Built 1968 Load: 18.1 t ADT: 15

LOCAL - 765TH

Poor

Over: WATERWAY

076341104, Cass, IA

Built 1900 Load: 18.1 t ADT: 35

STONE MILL RD

Poor

Over: ROCK RUN CREEK

080032203, Cedar, IA

Built 1974 Load: 18.1 t ADT: 50

KILLDEER

Poor

Over: BEAVER DAM CREEK

095212602, Cerro Gordo, IA

Built 1900 Load: 18.1 t ADT: 16

FM

Poor

Over: SEVEN MILE CREEK

067272401, Decatur, IA

Built 1957 Load: 18.1 t ADT: 131

FM

Poor

Over: HAWKEYE DOLBEE CHANNEL

072012002, Des Moines, IA

Built 1953 Load: 18.1 t ADT: 25

FM TULIP AVE

Poor

Over: W FORK CEDAR CRK OVRFLW

093192804, Franklin, IA

Built 1960 Load: 18.1 t ADT: 137

270 STREET

Poor

Over: MILL CREEK

067400401, Fremont, IA

Built 1959 Load: 18.1 t ADT: 26

305 AVENUE

Poor

Over: DRISCALL CREEK

070410706, Fremont, IA

Built 1958 Load: 18.1 t ADT: 63

VAIL AVE

Poor

Over: OVER CC RR

089232704, Hamilton, IA

Built 1932 Load: 18.1 t ADT: 578

LOCAL 25TH ST

Poor

Over: UPPER IOWA RIVER

100131303, Howard, IA

Built 1880 Load: 18.1 t ADT: 26

LOCAL

Poor

Over: SMALL

080112001, Iowa, IA

Built 1978 Load: 18.1 t ADT: 11

LOCAL

Poor

Over: STREAM

077102204, Keokuk, IA

Built 1969 Load: 18.1 t ADT: 26

LOCAL RD

Poor

Over: DRAINAGE

077280103, Madison, IA

Built 1956 Load: 18.1 t ADT: 60

LOCAL

Poor

Over: BRANCH N TIMBER CREEK

083192603, Marshall, IA

Built 1920 Load: 18.1 t ADT: 30

140TH ST

Poor

Over: MINERVA CREEK

085202703, Marshall, IA

Built 1912 Load: 18.1 t ADT: 62

FM-397TH ST

Poor

Over: FARM CREEK

073401504, Mills, IA

Built 1959 Load: 18.1 t ADT: 34

FM

Poor

Over: WEST FORK DD

085452701, Monona, IA

Built 1961 Load: 18.1 t ADT: 229

FAWN AVE

Poor

Over: BROKEN KETTLE CREEK

091470804, Plymouth, IA

Built 1953 Load: 18.1 t ADT: 11

FM

Poor

Over: TURKEY CREEK

081251401, Polk, IA

Built 1980 Load: 18.1 t ADT: 50

LOCAL

Poor

Over: BIG BEAR CREEK

080140808, Poweshiek, IA

Built 1951 Load: 18.1 t ADT: 60

BIG ROCK RD

Poor

Over: CREEK

080E10304, Scott, IA

Built 1923 Load: 18.1 t ADT: 1,060

LOCAL

Poor

Over: SMALL STREAM

801340, Shelby, IA

Built 1960 Load: 18.1 t ADT: 30

280TH ST

Poor

Over: GRANT 5 OPEN DITCH EXT

082220601, Story, IA

Built 1916 Load: 18.1 t ADT: 131

120TH ST

Poor

Over: EAST BR INDIAN CREEKH

085221801, Story, IA

Built 1919 Load: 18.1 t ADT: 15

150TH ST

Poor

Over: EAST BR INDIAN CREEK

085223401, Story, IA

Built 1950 Load: 18.1 t ADT: 30

560TH AVE

Poor

Over: HAM-STORY 1 OPEN DD

085233102, Story, IA

Built 1924 Load: 18.1 t ADT: 34

170TH STREET

Poor

Over: GRAND RIVER

072280703, Union, IA

Built 1957 Load: 18.1 t ADT: 46

Showing 18,951-19,000 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.