Mick, you're claiming I should believe a statistical study someone published instead of my own firsthand observations. I will sit firmly on my first impulse to make a suitably rude reply, and merely say I refuse to do so.

Tim, you're turning a shades-of-gray situation into a black-and-white one. You're perfectly right, you can't have cars at all without some degree of risk. But you have to draw a arbitary line somewhere. It's just like speed limits. The lower they are, the fewer accidents you get (as a general proposition, although I think low speed limits have some tendency to cause people to fail to pay attention because the driving is boring). So do you lower them to zero and have no accidents, or to you let everyone drive whatever speed they want, and have a real mess? It's a balancing thing.

Peter