A monorail utilizes a single rail serving as a track for passenger or freight vehicles. In most cases it is elevated, but monorails can also run at grade, below grade, or in subway tunnels. Vehicles are either suspended from or straddle a narrow guideway. Monorail vehicles are WIDER than the guideway that supports them.
This category is for vehicles and systems that are hybrids, that normally use and change between two modes: road and track. They drive on and off regular roads and overhead tracks, usually monorails, as needed; attach to tracks for longer trips, run on roads for shorter local trips.
Personal Rapid Transit (PRT) uses small automated cars to provide frequent and non-stop service from source station to destination station via a complex network of elevated guideways and switches.