I was driving down Venice Blvd. towards the beach, and noticed a couple riding motorized scooters on the edge of the street . The guy was in front, his female partner trailing behind. She suddenly fell, hitting the pavement HARD. Oblivious, he continued along side us for at least a half mile (before we pulled too far ahead of him to see him) without looking back, thinking she was right there behind him. If traffic had been heavier, she easily could have fallen into the right side lane, and been run over.
The wheels are so tiny, that if you hit a small bump or rock, you could easily eat it. I can't see this fad lasting very long.