Just about on topic I think...
Got threatened with a "****in' punch you in the face" by a fifty year old bloke a couple of days ago. I was driving the company van at the time and he took exception to my instinctive horn warning and emergency stop that I performed as he cut me up - he was too impatient to wait for me to pass so he could change lanes.
If my van doors hadn't been locked (this is Swansea after all

) he'd've punched me for sure - he was out of his Previa and pulling at the door handle of my van trying to get to me. Not an experience I'd care to repeat.
I phoned the local bobbies and gave the reg no. and a description etc. A PC returned my call within the hour and said that the only thing they could conceivably charge him with, was driving without due care and attention. To warrant a breach of the peace charge, the incident would have to be witnessed by a police officer. PC Jones asked me what I wanted him to do. I reasoned that a driving charge would be unlikely to stick(PC Jones agreed) but that a stern word delivered in person at this guy's home might be in order. PC Jones agreed and said he'd be round to 'have a word with this fellow' that afternoon. Fingers crossed then....