There is always one...

[mickdel]

As folk said, the only sensible thing to do, is pull over and let the idiot past at the first opportunity.    Those who threaten violence, are usually those hoping it doesn't come to that and are trying to intimidate you.  You can be sure if you lay a hand on him, he'd be onto the police to report an assault.

As someone said,  tag his number plate,  and report him.

It mucks your day up when you come across an idiot like that.