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

FM

Fair

Over: WILLOW CREEK

093442101, Plymouth, IA

Built 1967 Load: 30.4 t ADT: 589

FM

Fair

Over: WILLOW CREEK

093442102, Plymouth, IA

Built 1968 Load: 30.4 t ADT: 748

FM

Fair

Over: DRAINAGE DITCH NO. 22

090312902, Pocahontas, IA

Built 1970 Load: 30.4 t ADT: 828

LOCAL

Fair

Over: DD NO. 22

090321601, Pocahontas, IA

Built 1976 Load: 30.4 t ADT: 11

LOCAL

Fair

Over: LIZARD CREEK DD #53

091311902, Pocahontas, IA

Built 1977 Load: 30.4 t ADT: 11

LOCAL

Fair

Over: LIZARD CREEK

091313001, Pocahontas, IA

Built 1976 Load: 30.4 t ADT: 15

LOCAL

Fair

Over: DD #53 LIZARD CK

091321002, Pocahontas, IA

Built 1977 Load: 30.4 t ADT: 45

FM

Fair

Over: LIZARD CK DD #53

091321402, Pocahontas, IA

Built 1975 Load: 30.4 t ADT: 26

FM

Fair

Over: LITTLE CEDAR CK DD #181

091343203, Pocahontas, IA

Built 1971 Load: 30.4 t ADT: 679

FM

Fair

Over: DD #181 BIG BEAR CK

091343501, Pocahontas, IA

Built 1973 Load: 30.4 t ADT: 589

FM

Fair

Over: NO LIZARD CK DD #77

092320701, Pocahontas, IA

Built 1978 Load: 30.4 t ADT: 30

FM

Fair

Over: BEAVER CREEK

093320102, Pocahontas, IA

Built 1973 Load: 30.4 t ADT: 26

LOCAL

Fair

Over: PILOT CREEK

093321602, Pocahontas, IA

Built 1977 Load: 30.4 t ADT: 80

FM

Fair

Over: PILOT CREEK

093322502, Pocahontas, IA

Built 1975 Load: 30.4 t ADT: 20

LOCAL

Fair

Over: PILOT CREEK

093322602, Pocahontas, IA

Built 1977 Load: 30.4 t ADT: 30

LOCAL

Fair

Over: PILOT CREEK

093322701, Pocahontas, IA

Built 1977 Load: 30.4 t ADT: 30

FM

Fair

Over: N LIZARD CK DD #77

093332602, Pocahontas, IA

Built 1977 Load: 30.4 t ADT: 100

LOCAL

Fair

Over: N LIZARD CREEK

093332701, Pocahontas, IA

Built 1972 Load: 30.4 t ADT: 26

LOCAL

Fair

Over: N LIZARD CK DD #77

093333604, Pocahontas, IA

Built 1972 Load: 30.4 t ADT: 80

LOCAL

Fair

Over: DD #41 BIG CEDAR CK

093343401, Pocahontas, IA

Built 1977 Load: 30.4 t ADT: 330

US 6

Fair

Over: SILVER CREEK

1.0 MI. E OF SR L66, Pottawattamie, IA

Built 1961 Load: 30.4 t ADT: 2,770

FM

Fair

Over: FARM CREEK

074392801, Pottawattamie, IA

Built 1963 Load: 30.4 t ADT: 71

HONEYSUCKLE RD

Fair

Over: SLOCUM CREEK

075401103, Pottawattamie, IA

Built 1961 Load: 30.4 t ADT: 548

ORCHARD ROAD

Fair

Over: LITTLE MOSQUITO

075432804, Pottawattamie, IA

Built 1973 Load: 30.4 t ADT: 1,047

FM-MAHOGANY RD

Fair

Over: GREYBILL CREEK

076391301, Pottawattamie, IA

Built 1961 Load: 30.4 t ADT: 300

MAHOGANY ROAD

Fair

Over: BRANCH OF SILVER CREEK

076401603, Pottawattamie, IA

Built 1961 Load: 30.4 t ADT: 349

FM-WESTGATE RD

Fair

Over: PIGEON CREEK

077421703, Pottawattamie, IA

Built 1972 Load: 30.4 t ADT: 50

LOCAL

Fair

Over: STREAM

079152901, Poweshiek, IA

Built 2003 Load: 30.4 t ADT: 50

FM

Fair

Over: W FK GRAND RIVER

067310206, Ringgold, IA

Built 1979 Load: 30.4 t ADT: 270

300TH ST

Fair

Over: CREEK

080E41701, Scott, IA

Built 1970 Load: 30.4 t ADT: 1,390

FM

Fair

Over: E BR W NISHNABOTNA RIVER

079370602, Shelby, IA

Built 1972 Load: 30.4 t ADT: 588

B40

Fair

Over: FLOYD RIVER

095431001, Sioux, IA

Built 1977 Load: 30.4 t ADT: 1,795

FM

Fair

Over: DRY CREEK

096462102, Sioux, IA

Built 1967 Load: 30.4 t ADT: 1,077

LOCAL

Fair

Over: TWELVE MILE CREEK

086142906, Tama, IA

Built 2006 Load: 30.4 t ADT: 20

ALBIA RD

Fair

Over: BEAR CREEK

072142704, Wapello, IA

Built 1967 Load: 30.4 t ADT: 810

FM

Fair

Over: COTTON CREEK

074222704, Warren, IA

Built 1969 Load: 30.4 t ADT: 400

LOCAL ROAD

Fair

Over: DEER CREEK

077080403, Washington, IA

Built 1966 Load: 30.4 t ADT: 60

FM

Fair

Over: WOLF CREEK

0874414, Woodbury, IA

Built 1967 Load: 30.4 t ADT: 71

FM

Fair

Over: WOLF CREEK

0874415, Woodbury, IA

Built 1967 Load: 30.4 t ADT: 71

FM

Fair

Over: WRIGHT CREEK

088422102, Woodbury, IA

Built 1968 Load: 30.4 t ADT: 379

FM

Fair

Over: WOLF CREEK

088440503, Woodbury, IA

Built 1967 Load: 30.4 t ADT: 359

FM

Fair

Over: WHITE FOX CREEK

090253502, Wright, IA

Built 1967 Load: 30.4 t ADT: 26

FM

Fair

Over: UPPER IOWA RIVER

099060806, Allamakee, IA

Built 1974 Load: 30.5 t ADT: 69

FM

Fair

Over: SOUTH RIVER

073271204, Clarke, IA

Built 1968 Load: 30.5 t ADT: 29

US 30 WB

Fair

Over: UP RR

5.8 MI. E OF S JCT. US 61, Clinton, IA

Built 1974 Load: 30.5 t ADT: 4,500

IA 2

Fair

Over: W BRANCH LITTLE RIVER

1.2 MI. W OF W JCT. US 69, Decatur, IA

Built 1986 Load: 30.5 t ADT: 1,960

FM 150 ST

Fair

Over: HONEY CREEK

090053501, Delaware, IA

Built 1949 Load: 30.5 t ADT: 363

BUTTERFIELD RD.

Fair

Over: FARM CREEK

086021106, Jones, IA

Built 1974 Load: 30.5 t ADT: 176

IA 21

Fair

Over: ENGLISH RIVER

2.3 mi. N of Jct. IA. 22, Keokuk, IA

Built 1984 Load: 30.5 t ADT: 1,490

LINN-BENTON RD

Fair

Over: TRIB TO KNAPP CREEK

Benton-Linn Road, Linn, IA

Built 1972 Load: 30.5 t ADT: 1,530

Showing 5,701-5,750 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.