Now what do you do with tailgaters and someone squeezing in - into the (un)safe margin you have manufactured. At (say) speed limit 40mph across a set of traffic lights? The squeezer is exceeding the speed limit and is about to jam his brakes on as he runs out of his side of the road.
My reaction if I know the road is to pre-empt the situation by taking the space before he arrives, but it is a judgement and not always possible with multiple idiots.