Lassen County Bridge Report Card

Lassen County scores 75 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.

C75 / 100

Local infrastructure snapshot

Lassen County, California

Lassen County has 108 bridges in the National Bridge Inventory, with 8 rated poor and 3 rated scour-critical. Its poor-condition share of 7.4% is above the 4.9% statewide average. Poor-condition bridges carry about 2,382 daily vehicle crossings.

108Total Bridges

8Poor (7.4%)

72Fair (66.7%)

3Scour-Critical

Quote-Ready Local Facts

7.4%of county bridges are in poor condition, compared with 4.9% statewide and 6.7% nationally.

2,382daily vehicle crossings are on poor-condition bridges in the county.

3bridges are rated scour-critical, or 2.8% of the county bridge inventory.

Copyable Facts for Reporters

BridgeLookup.com gives Lassen County a Bridge Condition Exposure Score of 75/100 (C). The county has 108 bridges in the National Bridge Inventory, including 8 in poor condition and 3 rated scour-critical. Poor-condition bridges carry about 2,382 daily vehicle crossings. Poor condition does not mean unsafe; bridges judged unsafe are closed or restricted by transportation agencies.

Download all county report-card scores as CSV.

How the Score Breaks Down

Factor	Weight	County Value	Penalty
Poor-condition bridge share	40	7.4%	14.8
Poor-condition traffic exposure	25	1.3% of measured traffic	1.0
Scour-critical bridge share	20	2.8%	5.6
Average age vs national baseline	10	58 years vs 48 nationally	4.0
Traffic-data completeness	5	183,078 measured daily crossings	0.0

Score = 100 minus weighted penalties. The score is a comparative research signal, not an official safety rating. Read the full methodology.

County Comparisons

County Poor-Condition Share	7.4%
State Poor-Condition Share	4.9%
National Poor-Condition Share	6.7%
County Scour-Critical Share	2.8%
Average Bridge Age	58 years
Poor-Condition Traffic Exposure	2,382 vehicles/day

Bridges to Watch

Busiest Poor-Condition BridgeCR A21 / Mooney RD over Robbers Creek — 1,500 vehicles/day Oldest Listed BridgeJohnstonville RD over Susan River — built in 1921 All County BridgesBrowse every bridge record in Lassen County.

Top Bridges to Watch in Lassen County

Bridge	Reason	Condition	Daily Traffic	Year Built
CR A21 / Mooney RD over Robbers Creek	Poor condition + traffic exposure	Poor	1,500	1975
Cr417 (punkin Ctr) over Muddy Slough No 1	Poor condition + traffic exposure	Poor	200	1955
CR 305 (mapes Rd) over Whitehead Slough	Poor condition + traffic exposure	Poor	162	1978
RD 424 (bassett) over Willow Creek	Poor condition + traffic exposure	Poor	120	1960
RD 304 over Whitehead Slough	Poor condition + traffic exposure	Poor	100	1930
Cr246 (belfast Rd) over Willow Creek	Poor condition + traffic exposure	Poor	100	1975
CR 111 (pittville) over Beaver Creek	Poor condition + traffic exposure	Poor	100	1975
RD 311 over Deep Cut (baxter) Creek	Poor condition + traffic exposure	Poor	100	1978
State Route 299 over Pit River Overflow	Scour-critical foundation rating	Fair	1,800	1925
Cr213 (leavitt Ln) over Susan River	Scour-critical foundation rating	Fair	100	1970

Important safety note

Poor condition does not mean a bridge is unsafe. It means at least one major component has significant deterioration and the bridge is a priority for maintenance, repair, or replacement. Bridges judged unsafe are closed or restricted by transportation agencies.