Statistics reveal that more collisions between bicycles and motor vehicles occur on roads having specifically designated bicycle lanes than on roads having no such lanes. Hence, adding such lanes to existing roads is unlikely to enhance the safety of bicyclists. The argument is most vulnerable to criticism on the grounds that it ['overlooks the possibility that injuries sustained by bicyclists in accidents on roads with bicycle lanes are as serious, on average, as those sustained by bicyclists in accidents on roads without such lanes', 'takes for granted that any road alteration that enhances the safety of bicyclists also enhances the safety of motorists', 'concludes that adding bicycle lanes to roads will fail to enhance the safety of bicyclists on the grounds that only some roads that currently have such lanes are safe', 'fails to address the possibility that there are more bicyclists riding on roads with bicycle lanes than there are riding on roads without such lanes']