State profile · Above national median SD

South Dakota bridge safety

Condition ratings, load ratings, and structural-deficiency data for every public highway bridge in South Dakota - drawn straight from the FHWA National Bridge Inventory.

5,905
Public bridges
31.9%
Good condition
16.2%
Poor condition
16.2%
Structurally deficient

Data updated May 2026

Total Bridges

5,905

Public highway bridges in South Dakota

Good Condition

31.9%

1,885 bridges rated 7-9

-18.1pp vs 50% benchmark

Poor Condition

16.2%

959 bridges rated 0-4

Structurally Deficient

16.2%

959 bridges flagged for repair priority

9.2pp vs national avg 7.0%

South Dakota vs national bridge condition

South Dakota - Good condition share 31.9%
National avg

Share of bridges rated 7-9 on the FHWA 0-9 scale (deck, superstructure, substructure all good).

South Dakota - Structurally deficient share 54.1%
National avg

Lower is better. Bar maxes at 30% (worst-state ceiling). National average sits at 7.0%.

Condition Distribution

South Dakota34.6%47.8%17.6%GoodFairPoor (structurally deficient)
Bridge inventory deck-condition mix - South Dakota (FHWA NBI)

Counties (66)

Aurora 61 Beadle 153 Bennett 15 Bon Homme 126 Brookings 234 Brown 170 Brule 38 Buffalo 25 Butte 143 Campbell 15 Charles Mix 103 Clark 21 Clay 94 Codington 74 Corson 49 Custer 95 Davison 125 Day 37 Deuel 72 Dewey 28 Douglas 44 Edmunds 20 Fall River 80 Faulk 46 Grant 205 Gregory 51 Haakon 69 Hamlin 62 Hand 126 Hanson 62 Harding 49 Hughes 41 Hutchinson 161 Hyde 23 Jackson 89 Jerauld 35 Jones 37 Kingsbury 35 Lake 79 Lawrence 136 Lincoln 207 Lyman 114 Marshall 39 McCook 98 McPherson 14 Meade 217 Mellette 28 Miner 64 Minnehaha 395 Moody 87 Oglala Lakota 34 Pennington 350 Perkins 60 Potter 24 Roberts 157 Sanborn 53 Spink 176 Stanley 37 Sully 31 Todd 24 Tripp 90 Turner 143 Union 172 Walworth 34 Yankton 99 Ziebach 30

South Dakota 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 South Dakota on the same metric.

GU

Guam

15.25% top marginal rate
Structure
Progressive
Burden @ $100K
$59

WV

West Virginia

16.02% top marginal rate
Structure
Progressive
Burden @ $100K
$7,679
Selected

SD

South Dakota

16.24% top marginal rate
Structure
Progressive
Burden @ $100K
$5,905

IA

Iowa

20.01% top marginal rate
Structure
Progressive
Burden @ $100K
$20,753

VI

Virgin Islands

29.17% top marginal rate
Structure
Progressive
Burden @ $100K
$24

Bridges Needing Most Attention in South Dakota

Six lowest-condition bridges in South Dakota, ranked by composite NBI rating. Each is inspected at least every 24 months.

483 AVENUE

Structurally Deficient

Over: WHETSTONE RV

4.8E & 3.2N MILBANK, Grant, SD

Built 1962 Load: 0.9 t ADT: 25

202ND ST.

Structurally Deficient

Over: BEAR BUTTE CK

5.3E BEAR BUTTE, Meade, SD

Built 2000 Load: 0.9 t ADT: 50

45980 303 ST.

Structurally Deficient

Over: VERMILLION RV

6S & 7.8E IRENE, Clay, SD

Built 1909 Load: 1.8 t ADT: 15

460th Avenue

Structurally Deficient

Over: Big Coulee Creek

4S & 2W of Peever, Roberts, SD

Built 1950 Load: 2.2 t ADT: 22

197TH ST

Structurally Deficient

Over: TURTLE CK

1N & 1E ST LAWRENCE, Hand, SD

Built 1925 Load: 2.5 t ADT: 25

242 ST

Structurally Deficient

Over: CK

1.8E 11.0N PLANKINTON, Aurora, SD

Built 1917 Load: 2.7 t ADT: 101

All Bridges in South Dakota

370 AVE

Unknown

Over: I090

AURORA & BRULE CO LINE, Aurora, SD

Built 1965 ADT: 8,090

252ND ST (CR-34)

Unknown

Over: I090

2.6 W WHITE LAKE INTERCH, Aurora, SD

Built 1964 ADT: 8,090

I090 P

Unknown

Over: I090

WHITE LAKE INTERCHANGE, Aurora, SD

Built 1964 ADT: 8,090

377 AVE

Unknown

Over: I090

3.0 E WHITE LAKE INTERCH, Aurora, SD

Built 1965 ADT: 8,120

380 AVE (FAS 6119)

Unknown

Over: I090

6.0 E WHITE LAKE INTERCH, Aurora, SD

Built 1965 ADT: 8,120

384 AVE

Unknown

Over: I090

2.0 W PLANKINTON INTERCH, Aurora, SD

Built 1965 ADT: 8,120

SD258

Unknown

Over: I090

PLANKINTON INTERCHANGE, Aurora, SD

Built 1965 ADT: 8,490

US281

Unknown

Over: I090

US 281 INTERCHANGE, Aurora, SD

Built 1965 ADT: 9,890

392 AVE

Unknown

Over: I090

2 W EAST CO LINE, Aurora, SD

Built 1965 ADT: 9,890

RCP&E RR

Unknown

Over: JERSEY AVE.

JERSEY AVE., Beadle, SD

Built 1907 ADT: 4,220

COMMERCIAL ROUTE

Unknown

Over: US014

1.4 E JCT SD 37, Beadle, SD

Built 1960 ADT: 2,075

US014 W

Unknown

Over: US014 B

1N 1.6W BROOKINGS, Brookings, SD

Built 1970 ADT: 7,718

RCP&E RR

Unknown

Over: 6TH AVENUE

6TH AVENUE, Brookings, SD

Built 1936 ADT: 330

I029 S

Unknown

Over: 197 ST

1 S DEUEL CO LINE, Brookings, SD

Built 1970 ADT: 46

I029 S

Unknown

Over: 201 ST

3 N SD 30 INTERCH, Brookings, SD

Built 1970 ADT: 39

I029 S

Unknown

Over: 8TH ST S, RC,P&E RR

0.9 S US 14 INTERCH, Brookings, SD

Built 1966 ADT: 20

I029 N

Unknown

Over: 197 ST

1 S DEUEL CO LINE, Brookings, SD

Built 1970 ADT: 46

I029 N

Unknown

Over: 201 ST

3 N SD 30 INTERCH, Brookings, SD

Built 1970 ADT: 39

SD030

Unknown

Over: I029

SD 30 INTERCHANGE, Brookings, SD

Built 1970 ADT: 7,560

207 ST

Unknown

Over: I029

3 S SD 30 INTERCH, Brookings, SD

Built 1970 ADT: 9,960

209 ST

Unknown

Over: I029

2 N US14 BY PASS, Brookings, SD

Built 1970 ADT: 9,960

US014 B

Unknown

Over: I029

US14 BY-PASS INTERCHANGE, Brookings, SD

Built 1966 ADT: 9,960

US014

Unknown

Over: I029

US 14 & I 29 INTERCHANGE, Brookings, SD

Built 2017 ADT: 10,990

I029 N

Unknown

Over: 8TH ST S, RC,P&E RR

0.9 S US 14 INTERCH, Brookings, SD

Built 1966 ADT: 20

20th ST S

Unknown

Over: I029

2 S US 14 INTCH, Brookings, SD

Built 2022 ADT: 12,240

215 ST

Unknown

Over: I029

3 S US 14 INTERCH, Brookings, SD

Built 1966 ADT: 12,240

SD324

Unknown

Over: I029

SD 324 INTERCHANGE, Brookings, SD

Built 1966 ADT: 12,240

219 ST

Unknown

Over: I029

1 N MOODY CO LINE, Brookings, SD

Built 1966 ADT: 12,630

SECOND STREET

Unknown

Over: FIRST AVE NW

0.6 N JCT US12 - ABERDEEN, Brown, SD

Built 2003 ADT: 545

SECOND STREET

Unknown

Over: RAILROAD AVE SW

0.4 N JCT US12 - ABERDEEN, Brown, SD

Built 2003 ADT: 4,560

I090

Unknown

Over: MAIN ST, R&W RR

CHAMBERLAIN INTERCHANGE, Brule, SD

Built 1974 ADT: 1,355

I090 WB OFF RAMP

Unknown

Over: MAIN ST, R&W RR

CHAMBERLAIN INTERCH, Brule, SD

Built 1974 ADT: 1,355

I090 WB OFF RAMP

Unknown

Over: I090

0.9 SE CHAMB INTERCHANGE, Brule, SD

Built 1974 ADT: 7,250

SD050

Unknown

Over: I090

E CHAMBERLAIN INTERCHANGE, Brule, SD

Built 1964 ADT: 7,260

348 AVE

Unknown

Over: I090

2.5 W SD 50 INTERCH, Brule, SD

Built 1964 ADT: 7,260

SD050

Unknown

Over: I090

PUKWANA INTERCHANGE, Brule, SD

Built 1964 ADT: 7,170

I090 W

Unknown

Over: 356 AVE

5.5 E SD 50 INTERCH, Brule, SD

Built 1964 ADT: 80

I090 E

Unknown

Over: 356 AVE

5.5 E SD 50 INTERCH, Brule, SD

Built 1964 ADT: 80

I090 W

Unknown

Over: 251 ST

2.9 W SD 45 N INTERCH, Brule, SD

Built 2006 ADT: 345

I090 E

Unknown

Over: 251 ST

2.9 W SD 45 N INTERCH, Brule, SD

Built 2007 ADT: 345

I090 W

Unknown

Over: SD045

SD45N INTERCHANGE, Brule, SD

Built 1963 ADT: 1,541

I090 E

Unknown

Over: SD045

SD45N INTERCHANGE, Brule, SD

Built 1963 ADT: 1,541

365 AVE

Unknown

Over: I090

2.0 W SD 45S INTERCH, Brule, SD

Built 1965 ADT: 7,670

SD045

Unknown

Over: I090

SD 45 SOUTH INTERCHANGE, Brule, SD

Built 1965 ADT: 8,090

BURL NORTHERN RR

Unknown

Over: COUNTY ROAD

5S 3.8W WILLOW LAKE, Clark, SD

Built 1929 ADT: 78

SD050

Unknown

Over: SD 50 WL, SO DAK OWNED R

2 NW OF VERMILLION, Clay, SD

Built 1981 ADT: 1,832

SD050 E

Unknown

Over: SD050 L

EAST EDGE OF VERMILLION, Clay, SD

Built 1977 ADT: 4,518

I029 S

Unknown

Over: US212

US 212 & I 29 INTERCHANGE, Codington, SD

Built 1970 ADT: 12,968

SD020

Unknown

Over: I029

I 29 & SD 20 INTERCHANGE, Codington, SD

Built 1974 ADT: 6,600

161 ST

Unknown

Over: I029

4 S SD 20 INTERCH, Codington, SD

Built 1974 ADT: 7,360

Showing 1-50 of 5,905 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.

Every figure on PlainBridge is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.