Many's the time I have needed to get off a motorway or DC but there's so much traffic in the inside lane I have to squeeze in, without cutting up.
They see what I'm trying to do and, illegally but very commonly, flash me to say 'yeah, your okay to pull in front' otherwise you'll miss your junction. I acknowledge their kindness with a raised hand or a couple of hazard light flashes and everyone's happy
You can't always see or know when you need to get off a road in heavy traffic, in an unfamiliar area, or when a line of HGVs the size of Big Ben are obscuring your view. And talking of HGVs, they would be done every day as they elephant past another elephant. If you make them pull over only when a safe distance is reached god knows when the rest of us will eventually get past!
So if this whole debate revolves around how to educate people to drive carefully how is it any different to other walks of life? Please indulge me...
If a burglar continues to be a burglar, despite a fine or education, he is usually taken out of society for a while at her majesty's pleasure. Now then, the people who tailgate and cause accidents will generally have to pay the price with their insurance. If insurance companies heavily load the culprit's premium for this particular fault you would effectively legislate them off the road, (I know it wouldn't work for the very wealthy but it's a start). So, in the same way as with a burglar, you will take the bad driver out of highway society.
The idea that you can educate everyone, or most, to drive better is fallacious IMHO, just like you will never educate people not to 'burglar' or drop litter.
Hope that made sense?