High Quality Content by WIKIPEDIA articles! The Spanish solution (also called Barcelona solution) has two railway platforms, one on each side of the line, to speed up boarding and alighting: passengers board from one side and alight to the other. If there are three platforms (one island platform and two side platforms) shared between two tracks, generally the center platform will be a shared exit platform, as there is no benefit in segregating arriving passengers. At most locations doors for passenger exit open a few seconds before those for entry.