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

HOLY FAMILY LANE

Good

Over: CREEK

088E13512, Dubuque, IA

Built 2020 Load: 16.2 t ADT: 5

FM

Good

Over: SOLFERINO CREEK

066051304, Lee, IA

Built 1978 Load: 16.2 t ADT: 370

WILDWOOD RD

Good

Over: SMALL STREAM

1/4 mi. South of Hwy 44, Shelby, IA

Built 2012 Load: 16.2 t ADT: 41

2100TH ST

Good

Over: SNAKE CREEK

081383001, Shelby, IA

Built 2018 Load: 16.2 t ADT: 46

ULMUS

Good

Over: CREEK

096192808, Cerro Gordo, IA

Built 1967 Load: 16.3 t ADT: 35

4TH ST NE

Good

Over: WILLOW CREEK

000000000, Cerro Gordo, IA

Built 1961 Load: 16.3 t ADT: 1,093

262ND ST

Good

Over: WEST SILVER CREEK

081E32503, Clinton, IA

Built 1952 Load: 16.3 t ADT: 123

IA 2

Good

Over: MISSOURI RIVER

NEAR NEBRASKA CITY, NE, Fremont, IA

Built 1986 Load: 16.3 t ADT: 8,300

PARKWOOD CIRCLE

Good

Over: INDIAN CREEK

000000000, Pottawattamie, IA

Built 2008 Load: 16.3 t ADT: 684

150TH ST

Good

Over: KEIGLEY BRANCH

085243501, Story, IA

Built 1977 Load: 16.3 t ADT: 100

LITTLE CHURCH RD

Good

Over: TURKEY RIVER

096092706, Winneshiek, IA

Built 1977 Load: 16.3 t ADT: 148

STANGE RD(ISU)

Good

Over: IOWAY CREEK (STANGE)

0.1 MILE N OF SR 13TH ST, Story, IA

Built 1965 Load: 16.7 t ADT: 15,397

155TH

Good

Over: E BRANCH BEAVER DAM CK

094200405, Cerro Gordo, IA

Built 1970 Load: 16.8 t ADT: 47

LOCAL

Good

Over: MAPLE RIVER

089391603, Ida, IA

Built 1984 Load: 16.8 t ADT: 35

LOCAL

Good

Over: BIG CEDAR RIVER

071093404, Jefferson, IA

Built 1984 Load: 16.8 t ADT: 34

LOCAL

Good

Over: W FORK GRAND RIVER

067310101, Ringgold, IA

Built 1986 Load: 16.8 t ADT: 34

270TH ST

Good

Over: BIG WHISKEY SLOUGH

091433601, Plymouth, IA

Built 1990 Load: 16.9 t ADT: 11

DELTA AVE

Good

Over: STREAM

093050604, Clayton, IA

Built 1955 Load: 17.0 t ADT: 16

390TH ST

Good

Over: SMALL STREAM

091063101, Clayton, IA

Built 1958 Load: 17.0 t ADT: 79

FM HONEY CK RD

Good

Over: SMALL STREAM

089051005, Delaware, IA

Built 1957 Load: 17.0 t ADT: 275

BUSINESS 30

Good

Over: SPRING CREEK

0.13miEjctBus30&LisbonBlV, Linn, IA

Built 1951 Load: 17.0 t ADT: 1,895

140TH

Good

Over: E BR BEAVER DAM CREEK

094201601, Cerro Gordo, IA

Built 1976 Load: 17.1 t ADT: 30

320TH ST

Good

Over: WHARAM CREEK

097201801, Cerro Gordo, IA

Built 1914 Load: 17.1 t ADT: 21

LOCAL

Good

Over: LITTLE ROCK RIVER

100421801, Osceola, IA

Built 1951 Load: 17.1 t ADT: 15

LOCAL

Good

Over: RICHLAND CREEK

082141904, Tama, IA

Built 2010 Load: 17.1 t ADT: 11

LOCAL

Good

Over: STREAM

074112802, Keokuk, IA

Built 1999 Load: 17.2 t ADT: 80

RANCHERO RD

Good

Over: DRAINAGE

CITY BRIDGE NO. 27, Black Hawk, IA

Built 1973 Load: 17.4 t ADT: 1,638

LOCAL

Good

Over: STEEL CREEK

068240205, Decatur, IA

Built 1999 Load: 17.4 t ADT: 11

FM

Good

Over: W FORK BATTLE CREEK

088412201, Ida, IA

Built 2009 Load: 17.4 t ADT: 26

LOCAL

Good

Over: SMALL

089461401, Woodbury, IA

Built 2008 Load: 17.4 t ADT: 34

LOCAL

Good

Over: SMALL STREAM

089091604, Buchanan, IA

Built 2010 Load: 17.5 t ADT: 51

FM

Good

Over: PARADISE CREEK

083401401, Crawford, IA

Built 1988 Load: 17.5 t ADT: 5

LOCAL

Good

Over: STREAM

076131201, Keokuk, IA

Built 1998 Load: 17.5 t ADT: 71

LOCAL

Good

Over: BUNCOMB CREEK

087E22002, Dubuque, IA

Built 1977 Load: 17.8 t ADT: 20

LOCAL

Good

Over: SHORT CREEK

070270204, Decatur, IA

Built 2010 Load: 17.9 t ADT: 26

FM

Good

Over: SHORT CREEK

070271303, Decatur, IA

Built 1994 Load: 17.9 t ADT: 15

LOCAL

Good

Over: MOUTH OF CANOE

099072503, Winneshiek, IA

Built 1975 Load: 17.9 t ADT: 70

278TH

Good

Over: SHELL ROCK CREEK

096190103, Cerro Gordo, IA

Built 1965 Load: 18.0 t ADT: 62

OLD US 61

Good

Over: DEEP CREEK

083E33206, Clinton, IA

Built 1926 Load: 18.0 t ADT: 30

LOCAL

Good

Over: STREAM

069271202, Decatur, IA

Built 2003 Load: 18.0 t ADT: 11

2460 SIOUX AVE

Good

Over: DD #13

096231904, Hancock, IA

Built 1976 Load: 18.0 t ADT: 50

LOCAL

Good

Over: WEST FOR BATTLE CREEK

088412602, Ida, IA

Built 2003 Load: 18.0 t ADT: 21

LOCAL

Good

Over: CREEK

070340804, Taylor, IA

Built 2006 Load: 18.0 t ADT: 20

LOCAL

Good

Over: LITTLE SOAP CREEK

071133404, Wapello, IA

Built 2005 Load: 18.0 t ADT: 50

LOCAL

Good

Over: SOUTH FORK IOWA RIVER

090233602, Wright, IA

Built 1986 Load: 18.0 t ADT: 15

LOCAL

Good

Over: IOWA RIVER

091231503, Wright, IA

Built 1978 Load: 18.0 t ADT: 30

IA 51

Good

Over: HECHER CREEK

3.2 MI. N OF JCT. U.S. 18, Allamakee, IA

Built 1967 Load: 18.1 t ADT: 2,690

CRANE CREEK RD

Good

Over: TRIB TO ELK RUN CREEK

90-12-35-02-10, Black Hawk, IA

Built 1967 Load: 18.1 t ADT: 29

US 169

Good

Over: STREAM

4.7 MI. S OF S JCT. US 30, Boone, IA

Built 1935 Load: 18.1 t ADT: 3,370

SR M22

Good

Over: SIDE DITCH

At jct. SR M-22, Clay, IA

Built 1959 Load: 18.1 t ADT: 10

Showing 9,051-9,100 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.