I often ride my little motorbike to cut through very heavy holiday traffic. Filtering through, between rows of slow moving or stationary cars opens your eyes a bit as to what is going on in the drivers seat.
In my experience, not wanting to stereotype, but, young female drivers, in 'fashion cars' ie. fiat 500's, mini's etc. are the worst, some even have a tablet on their knee !! or dancing, 'phone users are usually 'white van man', 'top end' saloons' ie. Audi, Bmw. Merc etc. 'Mummies' are one of the scariest, either on the phone, usually texting, of facing the back seat, dealing with their offspring, or eating.
If you say anything to them, you will be met with a tirade of abuse.
The police could make a killing, clamping down on this dangerous crime, if they tried patrolling on unmarked little motorbikes that can easily push between traffic, these are not rare occurrences, I see it nearly every time I'm out, and I'm not particularly looking too hard.