As per all of the above really.
My mate reported 2 national express coaches going up the M6.
He sent off video evidence showing he was in lane 1 for 10 minutes with a long clear stretch ahead & the 2 coaches were driving unbelievably close together (tailgating) for the whole time in lane 2. No reason whatsoever why they couldn't have spent that time in lane 1.
he said that , at the same time, a car was trying to overtake them in lane 3 - but looked as though he was too frightened to pull alongside - consequently, the coaches and the idiot in lane 3 had set up a rolling road block:bang:
Maybe the laws should be changed to "submit dashcam evidence, we'll review it & send out a fine, if the same cars come up again, they'll get a fine plus have to do additional training course..."
There aren't enough police out there to enforce these rules - so use what is out there.
With regards using mobile phones. Sadly, the tints on all cars these days means that often the camera cannot see drivers on the mobile. this is a difficult one - video will show the car being driven, phone records will show a call being made & the fact that the phone was in the car BUT, the driver could argue it was on speaker.