The track on a railway or railroad is the structure consisting of the rails

The track on a railway or railroad is the structure consisting of the rails, fasteners, sleepers and ballast (or slab track), plus the underlying subgrade. Two subsystems of a ballasted track structure can be distinguished: the superstructure composed of rails, sleepers, ballast and sub ballast, and the substructure composed of a formation layer and the ground2.
Most important of rail track element is subjected to wheel loads must be able to securely sustain these loads applied in vertical, lateral, dipped and longitudinal directions and subsequently transfer them to the underlying supports. Rail is the track element, which is direct contact with the rolling stock. It is therefore very necessary, in particular from a safety point of view, to ensure the proper functioning of rails in the track system.