

Police use ultrasonic device to make sure drivers stay 3 feet from cyclists - caminante
http://arstechnica.com/tech-policy/2015/06/police-use-ultrasonic-device-to-make-sure-drivers-stay-3-feet-from-cyclists/

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Zigurd
Brilliant. Necessary. And all cars should have autonomous braking that keeps
them at least 3 feet from cyclists.

