Bridge to annoyance...

Have you ever noticed that some people like to stand or park on bridges that cross motorways? Why? It's not the best of views, tonnes of metal loudly roaring up and down, not to mention the huge amount of polluted air they must be inhaling. I can't see any logical reason why anyone would want to. All i think is it's either the Old Bill and their speed cameras [causing not only me to suddenly slow down] or some troublesome kids ready to drop an egg or two [i speak from experience of being such a victim]. Come on you bridge dwellers, there's better things to be doing!