This is because in an announcement made by the New York MTA, they are banning hoverboards from being brought to locations like the subway or to bus stations for obvious reasons. In case you haven’t heard, stories of hoverboards exploding are more common than we would like.
Thus bringing them onto crowded public spaces is obviously a bad idea. According to Fernando Ferrer, vice chair of the MTA board, “There have been reports about exploding batteries and certainly, you don’t want anything like that in a crowded subway car.” Other concerns are that people might ride them and get into accidents.
This is echoed by MTA Chief Safety Officer David Mayer who said, “For obvious reasons, it is not safe to use hoverboards, skateboards or other personal wheeled vehicles on station platforms. We’re equally concerned about the safety risk of bringing devices that pose fire hazards into the confined spaces inside trains and buses.”