What is "randstadrail"

RandstadRail is a public transportation rapid transit network in the southern part of the Randstad conurbation in the west of the Netherlands, connecting The Hague, Zoetermeer and Rotterdam. The network mainly uses former train and existing tram tracks, with a new flyover in The Hague and a new tunnel in Rotterdam. RandstadRail is a hybrid system of low-floor tram-train-like carriages used between The Hague and the city of Zoetermeer, and high-floor metro/subway-like carriages between The Hague and Rotterdam. The stations used by both lines have extended platforms with a high and a low part. Moreover, the network includes two bus lines.