Does not really answer the issue though. Most cities do not treat boards as legal to use on roads. Yes they make great campus or paved pathway tools but they still have no place on the streets with bicycles and motorized vehicles. When there is already poor bicycling infrastructure in most cities these seem to be more headache than helpful. All of the ones I see rolling around San Francisco move at about 10-15mph with bicycles passing them all the time. I have no numbers to back this claim but I am going to guess that a bicycle still has a shorter stopping distance than these.