&gt; Speed regulators, automatic enforcement of follow distance, ... have been summarily rejected by the general market.<p>Nonsense.<p>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>Here in Norway such facilities are available on small VW work vans as well as Toyota cars and of course luxury cars like the more expensive Mercedes, Jaguar, and Audi.<p>Of course I agree with your final point that at the moment there are many circumstances in which a human driver must take control but there are many small measures that can be taken by the car makes to further reduce the frequency and severity of accidents by adding features like adaptive cruise control, lane sensing, pedestrian and other obstacle sensing and avoidance, etc.  These will only be rejected when they are seen as extra cost add-ons but when they become common people will simply expect them to be fitted.