On my way into work this morning I saw single shoes in the middle of the road at no fewer than three different locations.

It's something I've noticed before, and I've always wondered how and why these shoes come to be sitting on or around the white line.

Have they been left behind by danger-loving pedestrians who keep getting in hazardous near-misses as they cross the road, always leaving one piece of footwear behind as they somersault out of the path of an unstoppable juggernaut?

Is the shoe all that's left of someone who's spontaneously combusted, probably due to the pent up anger and frustration that comes with trying to do something as simple as crossing the road in parts of Bradford?

Is it some game that the young people play today, a more edgy version of shove ha'penny or tiddlywinks, in which schoolchildren stand on the kerb and try to get their shoes nearest to the middle of the road?

Or is there a freaky loner, driving around Bradford with a box-ful of shoes on the passenger seat, tossing them out of his window at random locations?