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

US 30

Good

Over: DRAINAGE DITCH

0.5 mi. E of Jct. SR Y-52, Clinton, IA

Built 2006 Load: 30.1 t ADT: 3,500

D AVE

Good

Over: N RACCOON RIVER

00000, Dallas, IA

Built 2011 Load: 30.1 t ADT: 240

LOCAL

Good

Over: HAMMERS CREEK

089150101, Grundy, IA

Built 2009 Load: 30.1 t ADT: 70

LOCAL

Good

Over: MINERVA CREEK

086221501, Hardin, IA

Built 2004 Load: 30.1 t ADT: 10

LOCAL

Good

Over: DD

089220902, Hardin, IA

Built 2005 Load: 30.1 t ADT: 82

IA 175

Good

Over: STREAM

1.6 mi. W of W Jct US 59, Ida, IA

Built 2007 Load: 30.1 t ADT: 2,140

LOCAL

Good

Over: BR OF CHARITON RIVER

071201901, Lucas, IA

Built 2004 Load: 30.1 t ADT: 30

IA 3

Good

Over: DRAINAGE DITCH 53

2.3 mi. E of IA 4, Pocahontas, IA

Built 1984 Load: 30.1 t ADT: 2,390

IA 21

Good

Over: DEEP RIVER

1.0 MI. N OF JCT. IA 85, Poweshiek, IA

Built 1962 Load: 30.1 t ADT: 1,730

US 65

Good

Over: DRAINAGE DITCH

2.9 MILES N OF JCT US 30, Story, IA

Built 1987 Load: 30.1 t ADT: 2,110

FM

Good

Over: CREEK

078362203, Audubon, IA

Built 2002 Load: 30.2 t ADT: 110

LOCAL

Good

Over: PRARIE CK

083121102, Benton, IA

Built 2003 Load: 30.2 t ADT: 15

FM

Good

Over: SPRING BRANCH

083342303, Carroll, IA

Built 1984 Load: 30.2 t ADT: 60

FM

Good

Over: WASIPINICON CREEK

079032001, Cedar, IA

Built 2009 Load: 30.2 t ADT: 50

FM

Good

Over: TWO MILE CREEK

094142601, Chickasaw, IA

Built 1975 Load: 30.2 t ADT: 39

FM

Good

Over: LITTLE WAPSI

095133401, Chickasaw, IA

Built 1974 Load: 30.2 t ADT: 69

FM

Good

Over: SOUTH RIVER

073260505, Clarke, IA

Built 1982 Load: 30.2 t ADT: 26

105TH ST.

Good

Over: DEEP CREEK

083E50503, Clinton, IA

Built 1986 Load: 30.2 t ADT: 113

FM

Good

Over: WILLOW CREEK

082393501, Crawford, IA

Built 1988 Load: 30.2 t ADT: 50

LOCAL

Good

Over: MOSQUITO CREEK

080293201, Dallas, IA

Built 1980 Load: 30.2 t ADT: 51

68TH STREET

Good

Over: CREEK

000000000, Dallas, IA

Built 2003 Load: 30.2 t ADT: 4,116

LOCAL TULIP AVE

Good

Over: BEAVER CREEK

090192804, Franklin, IA

Built 1983 Load: 30.2 t ADT: 47

32ND ST.

Good

Over: SIBLES CREEK

083032405, Jones, IA

Built 1982 Load: 30.2 t ADT: 98

LOCAL

Good

Over: WATERMAN CREEK

096390601, O'Brien, IA

Built 1982 Load: 30.2 t ADT: 62

LOCAL

Good

Over: WATERMAN CREEK

097393002, O'Brien, IA

Built 1983 Load: 30.2 t ADT: 72

LOCAL

Good

Over: FLOYD RIVER

097410902, O'Brien, IA

Built 1981 Load: 30.2 t ADT: 30

LAKE AVE

Good

Over: PLYMOUTH CREEK

091450502, Plymouth, IA

Built 1977 Load: 30.2 t ADT: 159

FM C-38

Good

Over: PLYMOUTH CREEK

092453501, Plymouth, IA

Built 1977 Load: 30.2 t ADT: 1,267

LOCAL

Good

Over: SPRING CREEK

078221906, Polk, IA

Built 1986 Load: 30.2 t ADT: 71

FM-DOGWOOD RD

Good

Over: JORDAN CREEK

075393501, Pottawattamie, IA

Built 1982 Load: 30.2 t ADT: 15

WHIPPERWILL RD

Good

Over: PIGEON CREEK

077420901, Pottawattamie, IA

Built 1982 Load: 30.2 t ADT: 30

LOCAL

Good

Over: WEST BRANCH FLOYD RIVER

095451401, Sioux, IA

Built 1983 Load: 30.2 t ADT: 34

FM

Good

Over: SIXMILE CREEK

095462002, Sioux, IA

Built 1973 Load: 30.2 t ADT: 957

FM

Good

Over: DRY CREEK

096473402, Sioux, IA

Built 1973 Load: 30.2 t ADT: 529

FM

Good

Over: BURR OAK CREEK

097460104, Sioux, IA

Built 1973 Load: 30.2 t ADT: 1,087

LOCAL

Good

Over: BRANCH OF ROCK RIVER

097472301, Sioux, IA

Built 1983 Load: 30.2 t ADT: 131

LOCAL

Good

Over: STREAM

068220503, Wayne, IA

Built 2000 Load: 30.2 t ADT: 11

FM

Good

Over: NORTH BEAR CREEK

100071401, Winneshiek, IA

Built 1985 Load: 30.2 t ADT: 69

NB I-380

Good

Over: POYNER CREEK

0.2 mi. N of Jct. SR V49, Black Hawk, IA

Built 1983 Load: 30.3 t ADT: 13,450

FM 430TH ST

Good

Over: ELK CREEK

095353001, Clay, IA

Built 2004 Load: 30.3 t ADT: 240

340TH ST

Good

Over: LITTLE MEADOW CREEK

096360905, Clay, IA

Built 1981 Load: 30.3 t ADT: 103

240TH ST

Good

Over: YANKEE RUN CREEK

081E11701, Clinton, IA

Built 1969 Load: 30.3 t ADT: 73

270TH AVE

Good

Over: DEEP CREEK

083E32504, Clinton, IA

Built 1966 Load: 30.3 t ADT: 30

235TH AVE

Good

Over: DEEP CREEK

083E32808, Clinton, IA

Built 1965 Load: 30.3 t ADT: 26

135TH STREET

Good

Over: S BRANCH OF ELK RIVER

083E62005, Clinton, IA

Built 1965 Load: 30.3 t ADT: 35

US 69

Good

Over: YEADER CREEK

3.8 MILES S OF JCT I-235, Polk, IA

Built 1984 Load: 30.3 t ADT: 32,600

IA 21

Good

Over: BEAR CREEK

1.0 MI. S OF W JCT. US 6, Poweshiek, IA

Built 1962 Load: 30.3 t ADT: 800

US 69

Good

Over: IOWAY CREEK

0.6 mi. N of Jct. US 30, Story, IA

Built 1924 Load: 30.3 t ADT: 24,600

470TH

Good

Over: DEER CREEK

100193401, Worth, IA

Built 1972 Load: 30.3 t ADT: 30

130TH ST

Good

Over: SMALL STREAM

090072401, Buchanan, IA

Built 2016 Load: 30.4 t ADT: 50

Showing 10,101-10,150 of 20,753 bridges

Related

All states → | National rankings → | Understanding conditions → | SD bridges explained →
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.