I've wondered before whether self-driving cars, or even human drivers driving at a recommended speed, could perform some kind of traffic smoothing to avoid back

I've wondered before whether self-driving cars, or even human drivers driving at a recommended speed, could perform some kind of traffic smoothing to avoid backups and stop/start situations. Maps is pretty good these days at showing me when there's a slowdown ahead, but everyone just plows forward anyway at 70mph until they need to step on the brakes. If a subset of the cars just slowed down a bit in advance could we all drive at 50 without the stopping/starting/rear-ending? Seems like it'd be good press for Tesla if they had a 'Traffic Smoothing' setting.