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

200TH ST

Fair

Over: BRUSHY FORK CREEK

084362601, Carroll, IA

Built 2011 Load: 53.6 t ADT: 40

LOCAL

Fair

Over: LITTLE CEDAR RIVER

096150801, Floyd, IA

Built 1984 Load: 53.7 t ADT: 70

FM

Fair

Over: LONG CREEK

074041105, Louisa, IA

Built 1979 Load: 53.7 t ADT: 60

LOCAL

Fair

Over: DUTCH BRANCH

078391303, Shelby, IA

Built 1959 Load: 53.7 t ADT: 34

LOCAL

Fair

Over: DRAINAGE DITCH

079101407, Iowa, IA

Built 1984 Load: 53.8 t ADT: 45

IA 22

Fair

Over: RAMSEY CREEK

1.3 MI. W OF JCT. IA 1, Washington, IA

Built 1994 Load: 53.9 t ADT: 3,330

LOCAL

Fair

Over: REYNOLDS CREEK

0864203, Woodbury, IA

Built 2001 Load: 53.9 t ADT: 26

LOCAL RD

Fair

Over: PRICE CREEK

081100304, Iowa, IA

Built 1979 Load: 54.1 t ADT: 50

B AVENUE

Fair

Over: STREAM

069390906, Page, IA

Built 1990 Load: 54.1 t ADT: 29

IA 139

Fair

Over: STREAM

2.5 mi. N of Jct. IA 9, Winneshiek, IA

Built 1995 Load: 54.1 t ADT: 1,560

FM-IDELWOOD RD

Fair

Over: LITTLE SILVER CREEK

075410501, Pottawattamie, IA

Built 1979 Load: 54.5 t ADT: 34

G-14/WHIPPERWIL

Fair

Over: HONEY CREEK

077430509, Pottawattamie, IA

Built 1973 Load: 54.5 t ADT: 41

FM

Fair

Over: SCHUYLER CREEK

094162601, Floyd, IA

Built 1989 Load: 54.6 t ADT: 34

FM

Fair

Over: LITTLE FOX CREEK

068122002, Davis, IA

Built 1964 Load: 54.8 t ADT: 210

US 218 & IA 9

Fair

Over: SPRING CREEK

0.2 mi. N of S Jct. IA 9, Mitchell, IA

Built 1975 Load: 54.8 t ADT: 2,460

LOCAL

Fair

Over: SMALL STREAM

078311402, Guthrie, IA

Built 1962 Load: 54.9 t ADT: 20

FM

Fair

Over: LOST WATER CREEK

097181903, Floyd, IA

Built 1964 Load: 55.0 t ADT: 167

FM

Fair

Over: CREEK

086190602, Hardin, IA

Built 1979 Load: 55.1 t ADT: 29

IA 149

Fair

Over: NORTH SKUNK RIVER

2.5 mi. S of W Jct. IA 92, Keokuk, IA

Built 1986 Load: 55.1 t ADT: 2,540

US 63

Fair

Over: BIG BEAR CREEK

1.0 MILES N OF W JCT US 6, Poweshiek, IA

Built 1978 Load: 55.1 t ADT: 1,790

LOCAL (LWC)

Fair

Over: BRANCH BLUE CREEK

086090208, Benton, IA

Built 1987 Load: 55.2 t ADT: 39

LOCAL

Fair

Over: CREEK

089220103, Hardin, IA

Built 1979 Load: 55.2 t ADT: 91

US 18 WB

Fair

Over: LITTLE LIME CREEK

1.6 mi. E of S.R. S56, Cerro Gordo, IA

Built 1997 Load: 55.3 t ADT: 5,500

V AVE

Fair

Over: STREAM

084293402, Greene, IA

Built 1988 Load: 55.3 t ADT: 100

LOC TRACEY AVE

Fair

Over: N PICAYUNE CREEK

081413408, Harrison, IA

Built 2003 Load: 55.3 t ADT: 29

LOCAL

Fair

Over: UNNAMED STREAM

075133403, Keokuk, IA

Built 1967 Load: 55.3 t ADT: 34

IA 9

Fair

Over: LITTLE CEDAR RIVER

4.0 MI. E OF E JCT. US218, Mitchell, IA

Built 1979 Load: 55.3 t ADT: 1,900

US 69 & IA 9

Fair

Over: WINNEBAGO RIVER

2.2 mi. N of S.R. A44, Winnebago, IA

Built 1988 Load: 55.3 t ADT: 2,960

S PINE ST

Fair

Over: OTTER CREEK

000000000, Fayette, IA

Built 1979 Load: 55.4 t ADT: 397

FM

Fair

Over: CREEK

084E42303, Jackson, IA

Built 1998 Load: 55.5 t ADT: 330

FM

Fair

Over: CREEK

073081902, Jefferson, IA

Built 1950 Load: 55.6 t ADT: 50

12TH ST NW

Fair

Over: UP RR

000000000, Cerro Gordo, IA

Built 2005 Load: 55.7 t ADT: 10,174

LOCAL

Fair

Over: BR MUD CREEK

084111107, Benton, IA

Built 1994 Load: 55.8 t ADT: 15

FM E-41

Fair

Over: STREAM

083270604, Boone, IA

Built 1970 Load: 56.0 t ADT: 450

FM

Fair

Over: SMALL

069201203, Wayne, IA

Built 1976 Load: 56.0 t ADT: 25

FM

Fair

Over: GOOD WATER CREEK

070200410, Wayne, IA

Built 1984 Load: 56.0 t ADT: 310

LOCAL

Fair

Over: SMALL STREAM

094123501, Chickasaw, IA

Built 1982 Load: 56.1 t ADT: 34

LOCAL

Fair

Over: SIMPSON CREEK

095111701, Chickasaw, IA

Built 1983 Load: 56.1 t ADT: 51

FM

Fair

Over: SIMPSON CREEK

095113501, Chickasaw, IA

Built 1988 Load: 56.1 t ADT: 69

LOCAL

Fair

Over: CREEK

095143001, Chickasaw, IA

Built 1989 Load: 56.1 t ADT: 26

LOCAL

Fair

Over: DRY RUN

096113602, Chickasaw, IA

Built 1988 Load: 56.1 t ADT: 73

LOCAL

Fair

Over: CRANE CREEK

096121303, Chickasaw, IA

Built 1989 Load: 56.1 t ADT: 73

FM

Fair

Over: WALKER CREEK

070202304, Wayne, IA

Built 1976 Load: 56.1 t ADT: 300

LOCAL

Fair

Over: BR LITTLE BEAR CK

084093304, Benton, IA

Built 1990 Load: 56.6 t ADT: 20

FM

Fair

Over: IOWAY CREEK

086262202, Hamilton, IA

Built 1982 Load: 56.9 t ADT: 559

BLUEBIRD RD

Fair

Over: SMALL CREEK

086013405, Jones, IA

Built 2014 Load: 57.0 t ADT: 41

LOCAL

Fair

Over: BR HINKLE CREEK

084110401, Benton, IA

Built 1996 Load: 57.1 t ADT: 30

240TH AVE

Fair

Over: STREAM

099363301, Dickinson, IA

Built 1963 Load: 57.1 t ADT: 598

IA 92

Fair

Over: DES MOINES RIVER

0.5 mi. E of Jct. SR T25, Marion, IA

Built 1978 Load: 57.1 t ADT: 3,240

N64

Fair

Over: EAST RIVER

069320502, Taylor, IA

Built 1990 Load: 57.1 t ADT: 927

Showing 8,751-8,800 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.