County profile · official public datasets

Lincoln County, SD

207 public highway bridges tracked in the FHWA National Bridge Inventory: 34.3% rated Good, 48.3% Fair, 17.4% Poor.

207
Public bridges: 34.3%
Good condition: 17.4%
Poor condition

The verdict

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

Lincoln County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.

43rd
of 66 on Poor share: 17.4%
Poor-condition share: 207
public highway bridges: 1973
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.

Lincoln County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Lincoln County ranks #43 of 66 South Dakota counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 17.4%). Lincoln County, South Dakota contains 207 public highway bridges. Roughly 34.3% are rated “Good,” 48.3% “Fair,” and 17.4% “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

207

Public highway bridges in Lincoln County

Good condition

34.3%

71 of 207 rated 7-9

Fair condition

48.3%

100 of 207 rated 5-6

Poor condition

17.4%

36 of 207 rated 4 or below

In-state Poor-share rank

#43 of 66

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

Condition distribution

Share of 207 NBI-tracked bridges by lowest applicable component rating.

Good

34.3% (71)

Fair

48.3% (100)

Poor

17.4% (36)

Lincoln County's Poor-condition bridges carry 2,717 vehicle crossings a day

That is 0.6% of the county's reported daily bridge traffic on 17.5% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 75 crossings a day against 3,484 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 206 of 207 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

55.1% of Lincoln County's bridges have passed the 50-year mark

114 of the 207 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 34.3% 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 18.2% of the county's Poor-condition bridge traffic

466th Avenue over Saddle Creek, built 1964, carries 495 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 36-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 2,717 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1930s

39
1940s

17
1950s

24
1960s

30
1970s

10
1980s

15
1990s

17
2000s

13
2010s

32
2020s

10

What this shows Construction peaked in the 1930s, when 39 of the county's bridges still in the inventory were built, which is 18.8% of those with a recorded year. That cohort is now 85 to 94 years old in the 2024 inventory. Its average build year (1973) matches the South Dakota average (1975).

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

The 5 South Dakota counties nearest Lincoln County in number of bridges, with their condition splits. Its 17.4% Poor share is the 4th-lowest of these 6. Its average build year of 1973 against a peer-group mean of 1974 is in line with the group.

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

Bridge inventory size and condition shares for Lincoln County and the 5 South Dakota counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Brookings County	233	26.6%	50.6%	22.7%	1973
Meade County	215	43.7%	45.6%	10.7%	1979
Lincoln County (this page)	207	34.3%	48.3%	17.4%	1973
Grant County	205	35.1%	48.8%	16.1%	1980
Spink County	176	13.6%	52.8%	33.5%	1957
Brown County	170	32.9%	55.3%	11.8%	1983

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 Lincoln 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 Lincoln County, both outside South Dakota so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside SD (207 bridges here).

Marin County, CA · 207 bridges
Las Animas County, CO · 207 bridges
Shelby County, IA · 207 bridges
Washington County, IA · 207 bridges

Similar average build year

Nearest mean year-built outside SD (1973 here).

Jefferson County, AL · avg 1973 · 1,068 bridges
Erie County, NY · avg 1973 · 906 bridges
Davidson County, TN · avg 1973 · 832 bridges
Lancaster County, PA · avg 1973 · 801 bridges

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

All 207 Good 71 Fair 100 Poor 36

All bridges (207)

Sort:

Lincoln County Bridge Snapshot

Condition distribution

Lincoln County's Poor-condition bridges carry 2,717 vehicle crossings a day

55.1% of Lincoln County's bridges have passed the 50-year mark

One structure carries 18.2% of the county's Poor-condition bridge traffic

How Lincoln 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 (207)

468th Avenue

475th Avenue

296th Street

468th Avenue

477th Avenue

483rd Avenue

471st Avenue

475th Avenue

466th Avenue

284th Street

466th Avenue

481st Avenue

288th Street

464th Avenue

291st Street

280th Street

281st Street

466th Avenue

466th Avenue

283rd Street

294th Street

467th Avenue

467th Avenue

288th Street

468th Avenue

468th Avenue

468th Avenue

289th Street

469th Avenue

469th Avenue

469th Avenue

470th Avenue

470th Avenue

470th Avenue

284th Street

471st Avenue

471st Avenue

278th Street

472nd Avenue

473rd Avenue

473rd Avenue

474th Avenue

294th Street

279th Street

286th Street

475th Avenue

475th Avenue

274th Street

287th Street

296th Street

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