The Changi Airport Skytrain is an automated people mover (APM) that connects Terminals 1, 2 and 3 at Singapore Changi Airport. Traveling on the Skytrain is free. The third rail, formerly at the centre of the track, was moved to the side, and the Platform screen doors were fitted with full-height glass panels. The Changi Airport Skytrain uses the Mitsubishi Heavy Industries Crystal Mover automated people mover. This rolling stock entered service in 2006 and replaced the 16-year-old Adtranz C-100, making this the second generation of rolling stock in Changi Airport's Skytrain network. (https://en.wikipedia.org/wiki/Changi_Airport_Skytrain)