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

LOCAL

Good

Over: STREAM

091263008, Wright, IA

Built 1992 Load: 31.1 t ADT: 81

LOCAL

Good

Over: SMALL STREAM

092180305, Butler, IA

Built 2008 Load: 31.2 t ADT: 15

LOCAL

Good

Over: SMALL STREAM

092181302, Butler, IA

Built 2008 Load: 31.2 t ADT: 41

GRAND AVE.

Good

Over: SMALL STREAM

093170602, Butler, IA

Built 2002 Load: 31.2 t ADT: 59

LIBERTY AVENUE

Good

Over: SMALL

092173602, Butler, IA

Built 2003 Load: 31.2 t ADT: 118

FM

Good

Over: DD NO 20

087323303, Calhoun, IA

Built 1981 Load: 31.2 t ADT: 15

FM 240TH AVE

Good

Over: LITTLE MUDDY CREEK

097363208, Clay, IA

Built 1987 Load: 31.2 t ADT: 240

FM

Good

Over: DRAINAGE DITCH

092483602, Plymouth, IA

Built 1994 Load: 31.2 t ADT: 390

LOCAL

Good

Over: PILOT CREEK

093331302, Pocahontas, IA

Built 1980 Load: 31.2 t ADT: 20

FM

Good

Over: FARM CREEK

074391202, Pottawattamie, IA

Built 1981 Load: 31.2 t ADT: 45

66 ST

Good

Over: BRE STEW CK

084122801, Benton, IA

Built 2000 Load: 31.3 t ADT: 11

NW RAMP

Good

Over: POYNER CREEK

AT JCT. S.R. V49, Black Hawk, IA

Built 1983 Load: 31.3 t ADT: 1,370

E 63 (110TH)

Good

Over: MILL CREEK

082021001, Cedar, IA

Built 2012 Load: 31.3 t ADT: 30

FM

Good

Over: STEADY RUN CREEK

074121602, Keokuk, IA

Built 2005 Load: 31.3 t ADT: 50

US 71

Good

Over: SIN CREEK

4.5 mi. S of Jct. SR H-14, Montgomery, IA

Built 1970 Load: 31.3 t ADT: 1,390

FM

Good

Over: CREEK

078362203, Audubon, IA

Built 2002 Load: 31.4 t ADT: 110

YOUNG RD

Good

Over: INDIAN CREEK

88-11-09-01-10, Black Hawk, IA

Built 2005 Load: 31.4 t ADT: 59

W MT VERNON RD

Good

Over: TRIB TO CEDAR RIVER

90-13-28-01-10, Black Hawk, IA

Built 2006 Load: 31.4 t ADT: 25

475TH ST

Good

Over: SMALL STREAM

092150803, Butler, IA

Built 2004 Load: 31.4 t ADT: 59

VERMONT AVE

Good

Over: ROCK CREEK

080011502, Cedar, IA

Built 2011 Load: 31.4 t ADT: 71

FAWN HOLLOW

Good

Over: ROBERT'S CREEK

093050204, Clayton, IA

Built 1984 Load: 31.4 t ADT: 118

IA 4

Good

Over: DRAINAGE DITCH #110

6 mi. N of Jct. US 30, Greene, IA

Built 1993 Load: 31.4 t ADT: 1,950

LOCAL

Good

Over: CREEK

081352001, Audubon, IA

Built 1994 Load: 31.5 t ADT: 26

UNIVERSITY AVE

Good

Over: SMALL STREAM

000000000, Black Hawk, IA

Built 1969 Load: 31.5 t ADT: 6,993

LOCAL

Good

Over: CAMP CREEK

088342802, Calhoun, IA

Built 1986 Load: 31.5 t ADT: 20

KELLEY AVE

Good

Over: SMALL

081031404, Cedar, IA

Built 2009 Load: 31.5 t ADT: 60

LOCAL

Good

Over: TRIB CARTERS CREEK

067141502, Davis, IA

Built 2010 Load: 31.5 t ADT: 5

LOCAL

Good

Over: PHELPS CREEK

089160603, Grundy, IA

Built 1987 Load: 31.5 t ADT: 59

LOC 2100 UNION

Good

Over: GOLLS CREEK

095230902, Hancock, IA

Built 1987 Load: 31.5 t ADT: 26

EBYS MILL RD

Good

Over: MAQUOKETA RIVER

085020307, Jones, IA

Built 2009 Load: 31.5 t ADT: 44

FM 280TH ST

Good

Over: LOTTS CREEK

096300501, Kossuth, IA

Built 1986 Load: 31.5 t ADT: 20

IA 175

Good

Over: DRAINAGE DITCH

1.9 mi. W of E jct IA 141, Monona, IA

Built 1973 Load: 31.5 t ADT: 1,200

IA 10

Good

Over: SIX MILE CREEK

1.7 mi. W of W jct SR K22, Sioux, IA

Built 1987 Load: 31.5 t ADT: 2,210

I-380

Good

Over: PRAIRIE CREEK

3.2 mi. N of Ia. 150, Benton, IA

Built 1983 Load: 31.6 t ADT: 17,900

320TH ST

Good

Over: E BR WAPSINONOC CR

079032901, Cedar, IA

Built 2013 Load: 31.6 t ADT: 90

300TH AVE

Good

Over: BR OF HONEY CREEK

071200902, Lucas, IA

Built 2019 Load: 31.6 t ADT: 21

US 63 SB

Good

Over: WAPSIPINICON RIVER

4.5 MILE S OF S JCT US 18, Bremer, IA

Built 2008 Load: 31.7 t ADT: 2,800

US 63 NB

Good

Over: WAPSIPINICON RIVER

4.5 MILE S OF S JCT US 18, Bremer, IA

Built 2008 Load: 31.7 t ADT: 2,800

LOCAL

Good

Over: FIELD STREAM

082362602, Carroll, IA

Built 1995 Load: 31.7 t ADT: 50

130TH AVE.

Good

Over: SMALL STREAM

083E12202, Clinton, IA

Built 1987 Load: 31.7 t ADT: 62

215TH AVE

Good

Over: SMALL STREAM

087052404, Delaware, IA

Built 2004 Load: 31.7 t ADT: 20

W AVE

Good

Over: CRANE CREEK

095103208, Fayette, IA

Built 1989 Load: 31.7 t ADT: 128

FM

Good

Over: INDIAN CREEK

080201801, Jasper, IA

Built 2005 Load: 31.7 t ADT: 80

LOCAL

Good

Over: STREAM

076132003, Keokuk, IA

Built 1967 Load: 31.7 t ADT: 15

NB IA 13

Good

Over: OVER CC RR

0.4 MI. S OF SR E16, Linn, IA

Built 1973 Load: 31.7 t ADT: 3,600

FM

Good

Over: JOHNSON CREEK

099442702, Lyon, IA

Built 1980 Load: 31.7 t ADT: 40

IA 5 SB

Good

Over: SOUTH RIVER

0.2 mi. N of Jct. SR S31, Warren, IA

Built 2000 Load: 31.7 t ADT: 4,300

G61 310TH ST

Good

Over: THREE MILE CREEK

074301901, Adair, IA

Built 2003 Load: 31.8 t ADT: 379

LOCAL

Good

Over: DRY CREEK

083091502, Benton, IA

Built 1987 Load: 31.8 t ADT: 49

S TO W RAMP

Good

Over: POYNER CREEK

0.2 MI. N OF JCT. V49, Black Hawk, IA

Built 1983 Load: 31.8 t ADT: 1,290

Showing 10,251-10,300 of 20,753 bridges

Related

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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.