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 71

Fair

Over: STREAM

2.1 MI S OF S JCT IOWA 2, Page, IA

Built 1924 Load: 32.3 t ADT: 3,000

US 71

Fair

Over: STREAM

0.6 mi. S OF S JCT. IA 2, Page, IA

Built 1972 Load: 32.3 t ADT: 3,410

SB US 75

Fair

Over: DRY CREEK

2.3 mi. N of SR C60, Plymouth, IA

Built 1948 Load: 32.3 t ADT: 7,000

SB US 75

Fair

Over: DRY CREEK

1.5 mi. S of SR C44, Plymouth, IA

Built 1948 Load: 32.3 t ADT: 7,000

FM

Fair

Over: DRAINAGE

091462303, Plymouth, IA

Built 1966 Load: 32.3 t ADT: 190

IA 4

Fair

Over: DRAINAGE DITCH

1.5 mi. N of jct SR C56, Pocahontas, IA

Built 1991 Load: 32.3 t ADT: 2,420

FM

Fair

Over: SMALL STREAM

078402402, Shelby, IA

Built 1958 Load: 32.3 t ADT: 29

IA 2

Fair

Over: EAST 102 RIVER

At Jct. SR N-44, Taylor, IA

Built 1978 Load: 32.3 t ADT: 1,130

LOCAL

Fair

Over: IOWA RIVER

092242402, Wright, IA

Built 1987 Load: 32.3 t ADT: 63

LOCAL

Fair

Over: COTA CREEK

097031004, Allamakee, IA

Built 1982 Load: 32.4 t ADT: 26

FM

Fair

Over: BRANCH PAINT CREEK

097043607, Allamakee, IA

Built 1960 Load: 32.4 t ADT: 137

FM

Fair

Over: BRANCH VILLAGE CREEK

098030206, Allamakee, IA

Built 1925 Load: 32.4 t ADT: 570

FM

Fair

Over: BRANCH VILLAGE CREEK

098030706, Allamakee, IA

Built 1947 Load: 32.4 t ADT: 668

LOCAL RD

Fair

Over: VILLAGE CREEK

098052407, Allamakee, IA

Built 1965 Load: 32.4 t ADT: 44

LOCAL

Fair

Over: BR COON CREEK

098061804, Allamakee, IA

Built 1977 Load: 32.4 t ADT: 5

LOCAL

Fair

Over: BR WATERLOO CREEK

100060802, Allamakee, IA

Built 1953 Load: 32.4 t ADT: 20

MAIN ST

Fair

Over: UNIV BR DRY RUN CREEK

AT 18TH ST, Black Hawk, IA

Built 1962 Load: 32.4 t ADT: 9,191

LOCAL KING AVE

Fair

Over: SMALL STREAM

087092602, Buchanan, IA

Built 1970 Load: 32.4 t ADT: 62

FM VINCENT AV

Fair

Over: SMALL STREAM

088071502, Buchanan, IA

Built 1955 Load: 32.4 t ADT: 137

LOCAL 255TH ST

Fair

Over: SMALL STREAM

088082305, Buchanan, IA

Built 2006 Load: 32.4 t ADT: 11

LOCAL 240TH ST

Fair

Over: LIME CR

088101401, Buchanan, IA

Built 1967 Load: 32.4 t ADT: 34

LOCAL 180TH ST.

Fair

Over: PRAIRIE CREEK

089071601, Buchanan, IA

Built 1997 Load: 32.4 t ADT: 20

FM

Fair

Over: SMALL STREAM

089082204, Buchanan, IA

Built 1970 Load: 32.4 t ADT: 59

FM

Fair

Over: SMALL STREAM

089082803, Buchanan, IA

Built 1960 Load: 32.4 t ADT: 34

175TH AVE

Fair

Over: SMALL STREAM

089100703, Buchanan, IA

Built 1995 Load: 32.4 t ADT: 33

FM

Fair

Over: DRAINAGE DITCH

090071003, Buchanan, IA

Built 1955 Load: 32.4 t ADT: 44

LOC 100TH ST

Fair

Over: STREAM

090090201, Buchanan, IA

Built 1995 Load: 32.4 t ADT: 128

DEAD END 115 ST

Fair

Over: SMALL STREAM

000000000, Buchanan, IA

Built 1968 Load: 32.4 t ADT: 11

FM

Fair

Over: STREAM

089071902, Buchanan, IA

Built 1965 Load: 32.4 t ADT: 982

310TH STREET

Fair

Over: STREAM

087102301, Buchanan, IA

Built 2005 Load: 32.4 t ADT: 51

250TH ST

Fair

Over: UNNAMED CREEK

8808240100, Buchanan, IA

Built 2010 Load: 32.4 t ADT: 41

US 18

Fair

Over: WAPSIPINICON RIVER

0.1 MI. E OF SR V14, Chickasaw, IA

Built 1978 Load: 32.4 t ADT: 2,280

NB I-35

Fair

Over: WEST CREEK

2.5 MI. NORTH OF IA 152, Clarke, IA

Built 2012 Load: 32.4 t ADT: 9,400

310TH ST

Fair

Over: MEADOW CREEK

097362601, Clay, IA

Built 1999 Load: 32.4 t ADT: 30

240TH AVE

Fair

Over: LITTLE MEADOWS

097362802, Clay, IA

Built 1999 Load: 32.4 t ADT: 123

FM 280TH ST

Fair

Over: STONEY CREEK

097381001, Clay, IA

Built 1965 Load: 32.4 t ADT: 270

LOCAL 185 ST

Fair

Over: PLUM CREEK

089041603, Delaware, IA

Built 1986 Load: 32.4 t ADT: 20

CHESTERMAN RD

Fair

Over: CREEK

088E10203, Dubuque, IA

Built 2014 Load: 32.4 t ADT: 71

FM

Fair

Over: SMALL STREAM

091E13008, Dubuque, IA

Built 1895 Load: 32.4 t ADT: 45

SYCAMORE ST

Fair

Over: BEE BRANCH

N OF E 15TH STREET, Dubuque, IA

Built 2011 Load: 32.4 t ADT: 2,147

FM 100 160TH ST

Fair

Over: BOONE RIVER

094260501, Hancock, IA

Built 1948 Load: 32.4 t ADT: 330

HWY 359

Fair

Over: S FORK IOWA RIVER

088221102, Hardin, IA

Built 1958 Load: 32.4 t ADT: 1,286

US 30

Fair

Over: STREAM

3.6 miles east of SR F-32, Harrison, IA

Built 2012 Load: 32.4 t ADT: 3,090

F20L EASTON TRAIL

Fair

Over: WILLOW CREEK

080420607, Harrison, IA

Built 2020 Load: 32.4 t ADT: 437

US 169

Fair

Over: DRAINAGE DITCH

2.4 mi. N of jct. IA 3, Humboldt, IA

Built 1985 Load: 32.4 t ADT: 3,020

COUNTY RD E-16

Fair

Over: WET CREEK

086043501, Jones, IA

Built 1968 Load: 32.4 t ADT: 727

170TH STREET

Fair

Over: SMALL CREEK

085031719, Jones, IA

Built 2001 Load: 32.4 t ADT: 47

X 99

Fair

Over: IOWA RIVER

073022602, Louisa, IA

Built 2014 Load: 32.4 t ADT: 570

K60(INDIAN AVE)

Fair

Over: LITTLE ROCK RIVER

098440702, Lyon, IA

Built 1960 Load: 32.4 t ADT: 230

LOCAL ROAD

Fair

Over: CREEK

100431601, Lyon, IA

Built 2003 Load: 32.4 t ADT: 21

Showing 6,251-6,300 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.