&gt;&gt; Lots of new cars have cruise control with front facing radar distance and closing speed measurement that feeds back to the engine management to slow the car if it is getting too close too fast. Such radar is also used to apply the brakes in case the driver fails to brake soon enough.<p>I didn&#x27;t mean those.  I mean mandatory devices, things that totally replace the driver&#x27;s decision making.  A speed regulator would limit the car to the speed limit no matter what the driver wants.  Such a car would be electronically incapable of speeding.  That isn&#x27;t cruise control.  Trucks have had such devices for years.  And those radars for follow distance still allow drivers to tailgate.  I&#x27;m talking about a robot stepping in to prevent bad behaviour with no option to override.  That is what has been rejected by consumers year after year.  But that is what google is pitching.<p>Or how about: No seatbelt, no move.  That is dead simple to implement, but no US manufacturer has even attempted to market such a device.