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

W GRESHAM RD

Good

Over: TRIB QUARTER SECTION RUN

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

Built 1949 Load: 24.2 t ADT: 39

ROSE AVE

Good

Over: SMALL

082023602, Cedar, IA

Built 2009 Load: 24.2 t ADT: 45

120TH

Good

Over: LILLIBRIDGE CREEK

094202601, Cerro Gordo, IA

Built 1979 Load: 24.2 t ADT: 25

LARK

Good

Over: WEST FORK BEAVER DAM CR

094211302, Cerro Gordo, IA

Built 1978 Load: 24.2 t ADT: 275

PHEASANT

Good

Over: E BR BEAVER DAM CREEK

095203404, Cerro Gordo, IA

Built 1980 Load: 24.2 t ADT: 334

RAILROAD ST

Good

Over: BUCK CREEK

082391609, Crawford, IA

Built 2023 Load: 24.2 t ADT: 36

LOCAL

Good

Over: RICHLAND CREEK

082162102, Tama, IA

Built 2002 Load: 24.2 t ADT: 49

V43 N ELK RUN RD

Good

Over: TRIB TO ELK RUN CREEK

89-12-15-02-10, Black Hawk, IA

Built 1992 Load: 24.3 t ADT: 2,687

300TH ST

Good

Over: SMALL

079041601, Cedar, IA

Built 2007 Load: 24.3 t ADT: 105

R AVE

Good

Over: WILLOW CREEK

083413101, Crawford, IA

Built 2022 Load: 24.3 t ADT: 11

US 52

Good

Over: LUX CREEK

6.9 MI. S Jct US 61 & 151, Dubuque, IA

Built 1986 Load: 24.3 t ADT: 3,340

MASSEY MARINA LANE

Good

Over: SMALL CREEK

088E31404, Dubuque, IA

Built 2018 Load: 24.3 t ADT: 320

50TH ST.

Good

Over: UNAMED CR

091091703, Fayette, IA

Built 1985 Load: 24.3 t ADT: 59

364TH AVE

Good

Over: SUGAR CREEK

084E43502, Jackson, IA

Built 2020 Load: 24.3 t ADT: 59

110TH AVE

Good

Over: BIG BEAR CREEK

084022802, Jones, IA

Built 1989 Load: 24.3 t ADT: 26

FM

Good

Over: WATERMAN CREEK

095391001, O'Brien, IA

Built 1953 Load: 24.3 t ADT: 797

LOCAL

Good

Over: RESV. OVERFLOW

068180104, Appanoose, IA

Built 1991 Load: 24.4 t ADT: 91

OWEN RD

Good

Over: TRIB TO CRANE CREK

90-11-21-04-10, Black Hawk, IA

Built 1992 Load: 24.4 t ADT: 29

180TH ST

Good

Over: SMALL STREAM

081021501, Cedar, IA

Built 2002 Load: 24.4 t ADT: 45

W AVE

Good

Over: WILLOW CREEK

082392601, Crawford, IA

Built 2023 Load: 24.4 t ADT: 26

N AVE

Good

Over: PARADISE CREEK

083401001, Crawford, IA

Built 2021 Load: 24.4 t ADT: 11

K AVE

Good

Over: MIDDLE SOLDIER RIVER

08413001 0.6 Mi E NE Cor, Crawford, IA

Built 2014 Load: 24.4 t ADT: 26

US 63

Good

Over: 12 MILE CREEK

1.1 MI S OF S JCT SR D65, Tama, IA

Built 1956 Load: 24.4 t ADT: 3,690

LOCAL 270TH ST

Good

Over: SMITH CR

088083601, Buchanan, IA

Built 2004 Load: 24.5 t ADT: 73

IA 13

Good

Over: TURKEY RIVER OVERFLOW

0.3 mi. N of Jct. IA #56, Clayton, IA

Built 1982 Load: 24.5 t ADT: 2,800

160TH ST

Good

Over: STREAM

082E40501, Clinton, IA

Built 1962 Load: 24.5 t ADT: 21

340TH ST

Good

Over: HONEY CREEK

082370702, Crawford, IA

Built 2012 Load: 24.5 t ADT: 72

165TH ST

Good

Over: WELCH CREEK

082400704, Crawford, IA

Built 2020 Load: 24.5 t ADT: 36

M56 370TH ST

Good

Over: MILLER CREEK

0.02 S NW Cor Sec 3 Haye, Crawford, IA

Built 2017 Load: 24.5 t ADT: 15

360TH ST

Good

Over: HOCKETT CREEK

083371602, Crawford, IA

Built 2019 Load: 24.5 t ADT: 11

LOCAL

Good

Over: MALONY CREEK

083372602, Crawford, IA

Built 2007 Load: 24.5 t ADT: 51

360TH ST

Good

Over: MALONY CREEK

083372802, Crawford, IA

Built 2021 Load: 24.5 t ADT: 26

G AVE

Good

Over: HANNAH CREEK

084370301, Crawford, IA

Built 2022 Load: 24.5 t ADT: 35

FM

Good

Over: BENTON CREEK

084371502, Crawford, IA

Built 2010 Load: 24.5 t ADT: 40

DELOIT BLVD

Good

Over: SMALL STREAM

084380506, Crawford, IA

Built 2022 Load: 24.5 t ADT: 41

LOCAL

Good

Over: SMALL STREAM

084392405, Crawford, IA

Built 2003 Load: 24.5 t ADT: 62

LOCAL

Good

Over: EAST SOLDIER RIVER

084400201, Crawford, IA

Built 2010 Load: 24.5 t ADT: 21

L AVE

Good

Over: MINOR DRAINAGE

084403503, Crawford, IA

Built 2013 Load: 24.5 t ADT: 5

140TH ST

Good

Over: MIDDLE SOLDIER RIVER

.22 Mi South NW Cor Sec 2, Crawford, IA

Built 2014 Load: 24.5 t ADT: 11

B AVE

Good

Over: BEAMAN CREEK

085371001, Crawford, IA

Built 2019 Load: 24.5 t ADT: 30

B AVE

Good

Over: WHEELER CREEK

085381201, Crawford, IA

Built 2013 Load: 24.5 t ADT: 35

LOCAL

Good

Over: SMALL STREAM

085392603, Crawford, IA

Built 1994 Load: 24.5 t ADT: 82

200TH ST

Good

Over: SMALL STREAM

085403502, Crawford, IA

Built 2021 Load: 24.5 t ADT: 21

C AVE

Good

Over: SMALL STREAM

0.80 E NW Cor 15-85-41, Crawford, IA

Built 2021 Load: 24.5 t ADT: 15

320TH ST

Good

Over: CREEK

0.4 S NW Cor 2 -84-38, Crawford, IA

Built 1960 Load: 24.5 t ADT: 21

FM

Good

Over: MOSQUITO CREEK

079293403, Dallas, IA

Built 1984 Load: 24.5 t ADT: 79

FM GROUSE AVE

Good

Over: DD NO. 30

092211902, Franklin, IA

Built 1973 Load: 24.5 t ADT: 559

LOCAL

Good

Over: BR. HOSKINS CREEK

087392803, Ida, IA

Built 1999 Load: 24.5 t ADT: 5

LOCAL

Good

Over: HOG RUN

079100703, Iowa, IA

Built 1981 Load: 24.5 t ADT: 34

OAKDALE BLVD

Good

Over: MUDDY CREEK

000000000, Johnson, IA

Built 1996 Load: 24.5 t ADT: 5,803

Showing 9,501-9,550 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.