These contraptions are illegal here as are Segways, TBH i was surprised the electric scooters got allowed.
you also can not skateboard on public roads or sidewalks, but i think roller skates are okay for sidewalks.
In the 90ties i almost got in severe problems with the police for bumping so many skaters,,,,, good thing i did not follow thru on my plan back then to have a skater mark put on my car like pilots use to do for combat kills.