In my experience anything with two wheels, motorcycle, e-cycle, bicycle driven on a roadway is very dangerous. Especially if you put a teenager on one. Basically, two wheel converyances were known to me and my co-workers as " Donor Cycles" for obvious reasons. I now live in a "not traffic busy" area and was in a parking lot just yesterday when three kids, maybe 13-15, came riding by on e-cycles. I would estimate their speed at 20-25 mph, maybe a bit faster if capable. All I could think was "I hope one does not wind up on a slab."
If you ask me, same rules that apply to motorcycles should apply to anything with 2 wheels which is propelled by an engine or motor.