On one occasion, when towing my caravan, I came upon a section of motorway where the "slow lorries" warning was displayed. As I was passing one lorry, another one in front pulled out to overtake a truck in front of him. Both these lorries were obviously at their maximum, closely-matched speed, and it was clear that they were going to be stuck in lanes 1 and 2 for some time.
Meanwhile, the lorry I had passed then caught up and was in lane one, and alongside me. With my caravan in tow, I was not allowed to go into lane three, and other lorries had caught up behind me in both lanes one and two.
I would have preferred to return to lane 1, but my indicator was ignored, and the lorry drivers refused to drop back to allow me to move to lane 1. My greatest concern was, "what would happen if either one of the lorries in front of me, or my own vehicle, suffered a power failure or tyre blowout?"
I was keeping to a sensible distance from the lorry in front, but the lorries in lane 1 had all bunched up tight, and the lorry behind me was ridiculously close.
I think this was the worst case of collective madness by lorry drivers that I have ever come across.