PSD means a safety system that guarantees the safety of passengers and maintains a comfortable environment.

Installation of PSD are expanding in order to minimize the possibility of unexpected accident and to raise the satisfaction level of the passengers at the Subway and LRT which have become the important transportation in the biggest cities of the world.
PSD means a safety system preventing the fall of passengers or objects onto track side by the installation of fixed wall and automatic doors between platform and track, screen doors synchronized with the opening and closing of the train's doors, and maintains comfort environment on platform.