Anne Woiwode's points are well taken. Decades ago the dunes upon which the kids in this neighborhood slid on sleds & tobaggans in the winter time were invaded by snowmobiles; that eliminated non-motorized healthful exercise for safety reasons. I don't think a 15 mile an hour (for how long would that speed limitation last?) unprotected motor vehicle would be safe transport for a disabled person and it surely won't be for the pedestrian.
Who will enforce regulations?
Technically: Where & how would batteries be recharged? How and by whom will spilled electrolyte be cleaned up following an accident? Who, if anyone, will be responsible for recycling or otherwise disposing of used batteries?