County noise profile
Traffic noise in Santa Clara County, CA
Built from the US DOT National Transportation Noise Map (2020, 30-metre modeling grid, tract aggregation per Seto & Huang 2023) — the same public dataset used in the economics literature on what noise does to home values.
Average transportation noise (population-weighted)
46.8 dB
Residents above 60 dB
8%
Residents above 70 dB
3%
Population covered
1,924,379
Census tracts analyzed
408
Median home value
$1,555,600
What noise costs here
Estimated capitalized cost per median home
$15,961 – $37,241
Homebuyers pay a measurable premium for quiet. Using quasi-experimental evidence from highway noise-barrier construction, Moretti & Wheeler (2025) find prices rise 6.8% within 100 metres of new barriers — roughly 0.95% of home value per decibel of abatement. Applied to this county's average exposure of 46.8 dB and median home value of $1,555,600, the mid-range estimate is $26,601 (1.7% of value) — a stylized $10,640 per resident.
This is a research-based range, not a prediction of any specific property's value change. Source: NBER Working Paper 34298 (Moretti & Wheeler, 2025). Exposure varies street by street — averages hide the difference between a cul-de-sac and a frontage road.
Noise is one factor. A site decision needs all of them.
Our reports combine street-level noise exposure with demographics, traffic volumes, safety, schools, home values, and brand fit — every figure cited to its public source.
Data sources:US DOT/BTS National Transportation Noise Map (2020; all transportation modes; public domain), tract aggregation per Seto & Huang (2023); US Census Bureau ACS (median home values); NBER Working Paper 34298 (Moretti & Wheeler, 2025) for the capitalization methodology. Learn our methodology. Generated 2026-07-07.