More terrorism and intimidation on the commute

This morning was icy. Cars were frosty. Tyres cold and braking distances likely to be longer than usual. But we had Mr Idiot approach us at speed, tailgating and flashing for no obvious reason... Terrified we were gone to be rammed we stopped assuming that if he was in that much of a rush in dangerous conditions he could go off and kill somebody else. Instead the driver stopped behind us. We didn't wait for a confrontation. Incident was reported to the police but feedback is that they don't know who it was and can't identify the vehicle. This is despite reporting multiple instances of the similar problems on this stretch of road at the same time of day and promises that road policing does happen. This looks like things can only continue until this driver causes the death of himself, us and others. I am frustrated that having raised this issue to the highest level I am still suffering this terrorism on my commute to work and am being left to do all of my own policing. I failed to identify this driver so nothing happens. Until we have dead. Maybe. What am I supposed to do? Just not leave the house???