I was walking in a narrow street in Granada, Spain yesterday and two guys on their scooters where going at 40mph, on a street meant mostly for pedestrians. They pollute like cars (the stink is the same, even if smaller engine.) When people talk about cars ruining cities designed for walking, they should include scooters. They look cute in movies but they are not so pleasant to have around in practice. I don't mind the electric scooters the type you stand on because if you're going really fast on a narrow pedestrian and you hit someone it won't be so fatal, and you will get hurt probably equally, so people generally don't ride them at maximum speed. Also, they're essential for take-away food delivery.