The Noise Wall Lie — Highway Barrier Effectiveness

Filters

Effectiveness

High (≥10 dB reduction)

Medium (7–9 dB reduction)

Low (<7 dB reduction)

Unprotected gap

Equity Finding: Neighborhoods over 75% white receive barrier protection at 2.4x the rate of majority-minority communities adjacent to the same highways.

Equity by Income

About

State DOTs spend over $500 million annually on highway noise barriers. This analysis tests whether barriers deliver the noise reduction promised in their engineering justifications, and whether barrier placement correlates with neighborhood demographics.

Data: BTS National Noise Map · FHWA Noise Barrier Inventory · Caltrans · ACS Demographics