The driver of the van, might, quite possibly, have been late for a delivery for his company! Maybe this is the reason for the impatience displayed. It does not however, excuse that appalling standard of driving shown on the video, with the potential for loss of life!
As you gave not gotten anywhere with plod, have you thought of contacting the Managing Director of the company whose can was being driven so irresponsibly? Find their name and personal business e-mail address, send them a copy of the video, with the time and date and ask for their comments. Send a copy to local newspapers, ask for their comments and inform the MD that this is what you are doing.
If you have been so (rightly, IMHO) upset, surely this needs to be followed up. If you can't get plod to act, maybe this particular MD will see the negative publicity that could be generated. They my well want to have a word with the driver themselves.