County profile · official public datasets

Placer County, CA

337 public highway bridges tracked in the FHWA National Bridge Inventory: 44.2% rated Good, 51.6% Fair, 4.2% Poor.

Compiled by PlainBridges

337
Public bridges: 44.2%
Good condition: 4.2%
Poor condition

The verdict

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

Placer County pairs a top-quartile lowest Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

Top 19%
lowest Poor share in state: 4.2%
Poor-condition share: 337
public highway bridges: 1976
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.

Placer County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Placer County ranks #11 of 58 California counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 4.2%). Placer County, California contains 337 public highway bridges. Roughly 44.2% are rated “Good,” 51.6% “Fair,” and 4.2% “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

337

Public highway bridges in Placer County

Good condition

44.2%

149 of 337 rated 7-9

Fair condition

51.6%

174 of 337 rated 5-6

Poor condition

4.2%

14 of 337 rated 4 or below

In-state Poor-share rank

#11 of 58

Among California counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 337 NBI-tracked bridges by lowest applicable component rating.

Good

44.2% (149)

Fair

51.6% (174)

Poor

4.2% (14)

Placer County's Poor-condition bridges carry 227,371 vehicle crossings a day

That is 5.4% of the county's reported daily bridge traffic on 4.2% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 16,241 crossings a day against 12,082 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 337 of 337 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

52.2% of Placer County's bridges have passed the 50-year mark

176 of the 337 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 44.2% 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 19.8% of the county's Poor-condition bridge traffic

ROSEVILLE PARKWAY over ANTELOPE CREEK, built 2000, carries 44,970 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 14-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 227,371 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

1
1920s

14
1930s

25
1940s

15
1950s

51
1960s

39
1970s

44
1980s

36
1990s

24
2000s

38
2010s

41
2020s

9

What this shows Construction peaked in the 1950s, when 51 of the county's bridges still in the inventory were built, which is 15.1% of those with a recorded year. That cohort is now 65 to 74 years old in the 2024 inventory. Its average build year is 1976, 6 years newer than the California average of 1970.

How Placer County compares with California's closest counties by inventory size

The 5 California counties nearest Placer County in number of bridges, with their condition splits. Its 4.2% Poor share is the 1st-lowest of these 6. Its average build year of 1976 against a peer-group mean of 1967 is 9 years newer.

Showing the 5 closest of 57 California counties eligible for comparison.

Bridge inventory size and condition shares for Placer County and the 5 California counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Stanislaus County	386	30.8%	55.7%	13.5%	1956
Monterey County	377	56.8%	35.5%	7.7%	1970
Solano County	373	44.8%	47.5%	7.8%	1975
San Mateo County	361	26%	64%	10%	1967
Mendocino County	357	34.7%	57.7%	7.6%	1969
Placer County (this page)	337	44.2%	51.6%	4.2%	1976

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 Placer 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 Placer County, both outside California so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside CA (337 bridges here).

Tama County, IA · 337 bridges
Cowley County, KS · 337 bridges
Ouachita County, LA · 337 bridges
Windham County, VT · 337 bridges

Similar average build year

Nearest mean year-built outside CA (1976 here).

Marion County, IN · avg 1976 · 958 bridges
Mohave County, AZ · avg 1976 · 641 bridges
Comanche County, OK · avg 1976 · 593 bridges
Prince George's County, MD · avg 1976 · 576 bridges

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

All 337 Good 149 Fair 174 Poor 14

All bridges (337)

Sort:

Placer County Bridge Snapshot

Condition distribution

Placer County's Poor-condition bridges carry 227,371 vehicle crossings a day

52.2% of Placer County's bridges have passed the 50-year mark

One structure carries 19.8% of the county's Poor-condition bridge traffic

How Placer County compares with California'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 (337)

WEIMAR CROSSROAD

N65-BLUE OAKS OFF

LINCOLN BLVD

RIVERSIDE AVE

BOWMAN ROAD

BOWMAN ROAD

INTERSTATE 80

CROTHER RD

MAGRA ROAD

STATE ROUTE 49

DOUGLAS-SUNRISE BL

STATE ROUTE 49

STATE ROUTE 49

STATE ROUTE 49

STATE ROUTE 89

RAMP/CONNECTOR 80

MAPLE STREET

INTERSTATE 80 EB

STATE ROUTE 65

STATE ROUTE 65

STATE ROUTE 65 SB

N65-BLUE OAKS OFF

STATE ROUTE 49

W80-E&W49-W80 RMPS

GALLERIA BLVD

SIERRA COLLEGE BL

STATE ROUTE 65 SB

STATE ROUTE 65 NB

STATE ROUTE 65 NB

STATE ROUTE 65 NB

STATE ROUTE 65

STATE ROUTE 65

STATE ROUTE 65

WHITNEY RANCH PRKY

STATE ROUTE 89

INTERSTATE 80

BAXTER ROAD

CISCO ROAD

CRYSTAL SPRINGS RO

DRUM FOREBAY RD

WB 80 ON-RAMP

SQUAW VALLEY RD

AUBURN-FORSTHILLRD

PALM AVE

GOLD HILL ROAD

FINNING MILL RD

DOG BAR ROAD

PACIFIC ST

NICOLAUS ROAD WB

NICOLAUS ROAD

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