RandstadRail is a network of trains and trams connecting The Hague, Rotterdam, and Zoetermeer. It uses high level trains between The Hague and Rotterdam on the former Hofpleinlijn railway line between the two cities. This service was formerly known as the Erasmuslijn. Since 2010, the line has connected to the rest of the Rotterdam Metro at Rotterdam Centraal Station and trains continue all the way to Slinge in the southern part of the city.
The tram lines originate in The Hague and serve Leidschendam and Zoetermeer using a fleet of Alstom Regio Citadis trams.
Two buses were added to the network in December 2012 to connect the Rodenrijs Randstadrail station to Zoetermeer.