service has been compared to a taxi or a horizontal lift (elevator).

Numerous PRT systems have been proposed but most have not been implemented. , only a handful of PRT systems are operational: Morgantown Personal Rapid Transit (the oldest and most extensive), in Morgantown, West Virginia, has been in continuous operation since 1975. Since 2010 a 10-vehicle 2getthere system has operated at Masdar City,