County profile · official public datasets

Lawrence County, SD

136 public highway bridges tracked in the FHWA National Bridge Inventory: 36% rated Good, 51.5% Fair, 12.5% Poor.

136
Public bridges: 36%
Good condition: 12.5%
Poor condition

The verdict

According to the Federal Highway Administration's 2024 National Bridge Inventory.

Lawrence County pairs a better-than-median Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

Top 41%
lowest Poor share in state: 12.5%
Poor-condition share: 136
public highway bridges: 1980
avg year built

Poor is an FHWA condition category from the lowest applicable component rating (4 or below), not a live crossing-safety or closure decision. Rankings cover counties with at least five public highway bridges.

Lawrence County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Lawrence County ranks #27 of 66 South Dakota counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 12.5%). Lawrence County, South Dakota contains 136 public highway bridges. Roughly 36% are rated “Good,” 51.5% “Fair,” and 12.5% “Poor.” Poor means the lowest applicable deck, superstructure, substructure, or culvert rating is 4 or below on the 0–9 NBI scale. It is a condition category, not a live safety or closure decision.

Responsible agencies inspect covered bridges on risk-based intervals under current NBIS rules and submit inventory data to FHWA annually. The list below shows every NBI-tracked bridge in the county. Use the “Sort by” controls to change the ordering, and click any row for its reported inspection date, traffic count, and condition fields.

Source: FHWA National Bridge Inventory. See methodology for full definitions.

Total bridges

136

Public highway bridges in Lawrence County

Good condition

36%

49 of 136 rated 7-9

Fair condition

51.5%

70 of 136 rated 5-6

Poor condition

12.5%

17 of 136 rated 4 or below

In-state Poor-share rank

#27 of 66

Among South Dakota counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 136 NBI-tracked bridges by lowest applicable component rating.

Good

36% (49)

Fair

51.5% (70)

Poor

12.5% (17)

Lawrence County's Poor-condition bridges carry 7,993 vehicle crossings a day

That is 2% of the county's reported daily bridge traffic on 12.5% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 470 crossings a day against 2,647 for a Good-condition one. A Poor rating is a condition category, not a closure or a live safety judgement; it means the lowest applicable component rating is 4 or below.

Computed over the 136 of 136 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

49.3% of Lawrence County's bridges have passed the 50-year mark

67 of the 136 bridges with a recorded construction year were built in 1974 or earlier. Age alone is not a defect: a well-maintained older bridge can rate Good, and 36% of this county's inventory does. Even so, this older cohort is the population from which future Poor ratings are drawn, which is why the age profile below matters alongside the condition split above.

Cutoff derives from the 2024 release year minus a 50-year design life. Source: FHWA National Bridge Inventory, 2024 release.

One structure carries 25% of the county's Poor-condition bridge traffic

COUNTY RD 014B over MILLER CK, built 1934, carries 2,000 vehicles a day, the most of any Poor-rated structure here. The county's Poor-condition exposure is concentrated rather than evenly spread, so the 17-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 7,993 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

2
1930s

5
1940s

3
1950s

3
1960s

18
1970s

49
1980s

8
1990s

20
2000s

17
2010s

5
2020s

6

What this shows Construction peaked in the 1970s, when 49 of the county's bridges still in the inventory were built, which is 36% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year is 1980, 5 years newer than the South Dakota average of 1975.

How Lawrence County compares with South Dakota's closest counties by inventory size

The 5 South Dakota counties nearest Lawrence County in number of bridges, with their condition splits. Its 12.5% Poor share is the 2nd-lowest of these 6. Its average build year of 1980 against a peer-group mean of 1971 is 9 years newer.

Showing the 5 closest of 65 South Dakota counties eligible for comparison.

Bridge inventory size and condition shares for Lawrence County and the 5 South Dakota counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Butte County	143	30.8%	57.3%	11.9%	1976
Turner County	143	38.5%	35.7%	25.9%	1984
Lawrence County (this page)	136	36%	51.5%	12.5%	1980
Bon Homme County	126	21.4%	50.8%	27.8%	1961
Hand County	126	24.6%	46%	29.4%	1961
Davison County	123	34.1%	48.8%	17.1%	1973

Each share is of that county's own total tracked bridges; peers are the counties with 5 or more bridges whose inventory size is closest to Lawrence County's. Source: FHWA National Bridge Inventory, 2024 release.

Nationwide counties with similar inventory size or average build year

Two NBI-derived peer sets for Lawrence County, both outside South Dakota so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside SD (136 bridges here).

Bullock County, AL · 136 bridges
Jackson County, AR · 136 bridges
Perry County, IL · 136 bridges
Lincoln County, KY · 136 bridges

Similar average build year

Nearest mean year-built outside SD (1980 here).

Tulsa County, OK · avg 1980 · 1,135 bridges
Miami-Dade County, FL · avg 1980 · 1,057 bridges
Pulaski County, AR · avg 1980 · 721 bridges
McLennan County, TX · avg 1980 · 714 bridges

Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.

All 136 Good 49 Fair 70 Poor 17

All bridges (136)

Sort:

Lawrence County Bridge Snapshot

Condition distribution

Lawrence County's Poor-condition bridges carry 7,993 vehicle crossings a day

49.3% of Lawrence County's bridges have passed the 50-year mark

One structure carries 25% of the county's Poor-condition bridge traffic

How Lawrence County compares with South Dakota's closest counties by inventory size

Nationwide counties with similar inventory size or average build year

Similar inventory size

Similar average build year

All bridges (136)

Mill Creek Road

UPPER REDWATER RD

CLEOPATRA ROAD

RIMROCK LODGE ROAD

WINTERVILLE ROAD

108TH AVE.

NASH ST

HOMESTAKE ROAD

NEMO ROAD

NEMO ROAD

EDEN RD

WHITEWOOD VALLEY

STATE PARK RD

WHITEWOOD VALLEY

I090 WB ON RAMP

HIGGINS GULCH

US085

COUNTY RD

SD034

I090 W

US085 S

US085 N

I090 E

I090 W

I090 E

JACKSON BLVD

GRANT STREET

US085

I090 W

I090 E

US014AEF

I090 E

I090 W

US014A

I090 E

I090 W

WALNUT STREET

I090 W

I090 WF

I090 E

I090 EB OFF RAMP

I090 W

CANYON STREET

US085 S

US085 S

KIRK RD

US014A PINE ST

US085 N

I090 E

COLORADO BLVD

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