So that much we know. What I have noticed over the past few years is something different, but possibly related: the reluctance of pedestrians to engage in negotiation for right of way. Time was, in this most self-deprecating and pointlessly apologetic of Europe’s cities that collision detection was default behaviour for pavement-dwellers. Older readers may remember a sketch in the BBC’s The Fast Show where ‘Indecisive Dave’ spent so long in trying to negotiate passage through a doorway with another person that he eventually just waved to his friends, said ‘See you later’ and went home.