Unlike many other metro systems around the world, "main line" MTR stations originally did not have toilet facilities available for public use. Passengers may use MTR staff toilets at all stations on request. In 2006, MTRCL said it would not consider retrofitting existing underground toilets, because of the challenge of installing new piping and toilet facilities. Only stations on the Airport Express and Disneyland Resort line had access to toilet facilities. All former KCR stations (on the East Rail line, West Rail line, and Tuen Ma line), merged into the MTR network in 2007, have public toilets.