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: DRAINAGE

074271003, Madison, IA

Built 1951 Load: 14.5 t ADT: 40

FM

Poor

Over: TIMBER CREEK

083170804, Marshall, IA

Built 1945 Load: 14.5 t ADT: 59

LOCAL

Poor

Over: MUD CREEK

085192104, Marshall, IA

Built 1946 Load: 14.5 t ADT: 41

CONCORD AVE

Poor

Over: UNNAMED CREEK

092481602, Plymouth, IA

Built 1949 Load: 14.5 t ADT: 11

LOCAL

Poor

Over: BEAR CREEK

080140702, Poweshiek, IA

Built 1950 Load: 14.5 t ADT: 60

LOCAL

Poor

Over: STREAM

081151401, Poweshiek, IA

Built 1980 Load: 14.5 t ADT: 20

FM

Poor

Over: DD #71

087360701, Sac, IA

Built 1920 Load: 14.5 t ADT: 20

710TH AVE

Poor

Over: MIDDLE MINERVA CREEK

085212204, Story, IA

Built 1953 Load: 14.5 t ADT: 60

LOCAL

Poor

Over: BRANCH FLANK CREEK

074221002, Warren, IA

Built 1965 Load: 14.5 t ADT: 46

FM

Poor

Over: WOLF CREEK

074221202, Warren, IA

Built 1955 Load: 14.5 t ADT: 110

LOCAL

Poor

Over: WILD CAT CREEK

084090803, Benton, IA

Built 1900 Load: 14.6 t ADT: 39

LOCAL

Poor

Over: PRAIRIE CK

085100204, Benton, IA

Built 1971 Load: 14.6 t ADT: 90

LOCAL - JASPER

Poor

Over: NISHNABOTNA RIVER

076372303, Cass, IA

Built 1959 Load: 14.6 t ADT: 46

CRYSTAL RD

Poor

Over: STREAM

092061104, Clayton, IA

Built 1920 Load: 14.6 t ADT: 44

LOCAL

Poor

Over: ZADIE CREEK

067271502, Decatur, IA

Built 1964 Load: 14.6 t ADT: 72

LOCAL

Poor

Over: STREAM

069252506, Decatur, IA

Built 1961 Load: 14.6 t ADT: 41

LOCAL

Poor

Over: STREAM

069270501, Decatur, IA

Built 1961 Load: 14.6 t ADT: 21

LOCAL

Poor

Over: CREEK

086241001, Hamilton, IA

Built 1918 Load: 14.6 t ADT: 131

MOBILE AVE

Poor

Over: ALLEN CREEK

081433402, Harrison, IA

Built 1957 Load: 14.6 t ADT: 11

S 104TH AVE E

Poor

Over: SMALL STREAM

078181903, Jasper, IA

Built 1978 Load: 14.6 t ADT: 30

LOCAL

Poor

Over: ROCK CR

084172701, Marshall, IA

Built 1942 Load: 14.6 t ADT: 62

LOCAL

Poor

Over: CREEK

071192003, Monroe, IA

Built 1970 Load: 14.6 t ADT: 40

LOCAL RD

Poor

Over: LOTTS CREEK

068292503, Ringgold, IA

Built 1900 Load: 14.6 t ADT: 20

FM

Poor

Over: CREEK

070100804, Van Buren, IA

Built 1977 Load: 14.6 t ADT: 40

LOCAL

Poor

Over: STREAM

080320902, Guthrie, IA

Built 1940 Load: 14.7 t ADT: 5

UNITY AVENUE

Poor

Over: BRANCH OF SILVER CREEK

099110902, Howard, IA

Built 1960 Load: 14.7 t ADT: 21

LOCAL

Poor

Over: SMALL STREAM

073042105, Louisa, IA

Built 1930 Load: 14.7 t ADT: 11

A26 (180TH ST)

Poor

Over: BIG SIOUX RIVER

099482103, Lyon, IA

Built 1977 Load: 14.7 t ADT: 1,017

LOCAL

Poor

Over: S COAL CREEK

074171201, Mahaska, IA

Built 1951 Load: 14.7 t ADT: 80

LOCAL

Poor

Over: DD 63

094330601, Palo Alto, IA

Built 1958 Load: 14.7 t ADT: 15

LOCAL

Poor

Over: LIZARD CREEK

094342502, Palo Alto, IA

Built 1921 Load: 14.7 t ADT: 21

320TH ST

Poor

Over: CREEK

090442701, Plymouth, IA

Built 1900 Load: 14.7 t ADT: 30

LYNX AVE

Poor

Over: BIG WHISKEY CREEK

090450402, Plymouth, IA

Built 1958 Load: 14.7 t ADT: 50

220TH ST

Poor

Over: DRAINAGE

091450501, Plymouth, IA

Built 1958 Load: 14.7 t ADT: 26

200TH ST

Poor

Over: PLYMOUTH CREEK

092443001, Plymouth, IA

Built 1952 Load: 14.7 t ADT: 15

200TH ST

Poor

Over: DRAINAGE

092492603, Plymouth, IA

Built 1959 Load: 14.7 t ADT: 30

FM

Poor

Over: MUD CREEK

074413602, Pottawattamie, IA

Built 1976 Load: 14.7 t ADT: 20

220TH STREET

Poor

Over: PIGEON CREEK

077432602, Pottawattamie, IA

Built 1925 Load: 14.7 t ADT: 5

LOCAL

Poor

Over: BEAR CREEK

080141304, Poweshiek, IA

Built 1935 Load: 14.7 t ADT: 26

305TH ST

Poor

Over: STREAM

080E31205, Scott, IA

Built 1976 Load: 14.7 t ADT: 143

LOCAL

Poor

Over: SMALL STREAM

071293502, Union, IA

Built 1973 Load: 14.7 t ADT: 15

POCAHONTAS AVE

Poor

Over: STREAM

087421702, Woodbury, IA

Built 1935 Load: 14.7 t ADT: 5

FM

Poor

Over: CEDAR RIVER

086100603, Benton, IA

Built 1968 Load: 14.8 t ADT: 324

FM

Poor

Over: CRANE CREEK

096111903, Chickasaw, IA

Built 1959 Load: 14.8 t ADT: 157

LOCAL

Poor

Over: DUGOUT CREEK

099380701, Dickinson, IA

Built 1967 Load: 14.8 t ADT: 11

LOCAL

Poor

Over: LITTLEFLOOD CREEK

095172501, Floyd, IA

Built 1987 Load: 14.8 t ADT: 29

LOC 215TH ST

Poor

Over: PIGEON CREEK

080413603, Harrison, IA

Built 1955 Load: 14.8 t ADT: 26

LOCAL

Poor

Over: PRAIRIE CREEK

080202701, Jasper, IA

Built 1923 Load: 14.8 t ADT: 47

FM

Poor

Over: MIDDLE RIVER

075281804, Madison, IA

Built 1935 Load: 14.8 t ADT: 11

FM

Poor

Over: BRANCH, SKUNK RIVER

081231303, Polk, IA

Built 1968 Load: 14.8 t ADT: 131

Showing 18,251-18,300 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.