Sleeper

A sleeper, comprising:

• a sleeper body having top and bottom sides, and effective rail laying band regions on the top side, wherein for each of the effective rail laying band regions a rail is adapted to reside thereon, and at least two seating regions correspond to and overlap with each of the effective rail laying band regions, each seating region adapted to have a respective rail fastener secured thereto;
• for each of the effective rail laying band regions, from the top side to the bottom side, wherein each respective through opening corresponds to a rail, and the respective through opening extends further in both lateral directions beyond the respective rail and the corresponding effective rail laying band region, and with two through openings arranged in a row that extends transverse to the effective rail laying band regions;
• and
• wherein for each through opening the cross sectional area thereof increases on at least a section from the bottom side to the top side of the sleeper body, and further, wherein the lateral extensions of the through opening are asymmetrical with respect to the corresponding effective rail laying band region, with a first farther extension that extends in a first direction being greater than a second farther extension that extends in a second direction.