Good question, I wasn't able to find details, just some basics: https://radiichina.com/beijing-installs-car-horn-detectors-to-battle-noise-pollution/ https://r

Good question, I wasn't able to find details, just some basics: https://radiichina.com/beijing-installs-car-horn-detectors-to-battle-noise-pollution/ https://radiichina.com/beijing-installs-car-horn-detectors-t... https://www.shine.cn/archive/district/jing-an/Crackdown-on-horn-cacophony/shdaily.shtml https://www.shine.cn/archive/district/jing-an/Crackdown-on-h...