Hmmm, why is the car in front of me braking?

https://www.youtube.com/watch?annotation_id=56e8daef-0000-29c7-b247-94eb2c08c4fa&feature=iv&src_vid=hWNKIyljLuY&v=byITEpvV0BM via /r/videos http://ift.tt/1UmtELn