High Quality Content by WIKIPEDIA articles! A railroad tie is a rectangular object used as a base for railroad tracks. Ties are members generally laid transverse to the rails, on which the rails are supported and fixed, to transfer the loads from rails to the ballast and subgrade, and to hold the rails to the correct gauge. Traditionally, ties have been made of wood, but concrete is now widely used. Steel ties and plastic composite ties are currently used as well, although far less than wood or concrete ties. As of January 2008, the approximate market share, in North America, for traditional and wood ties was 91.5%, whereas the approximate combined market share for (all) concrete, steel, azobe (exotic hardwood) and plastic composite ties was 8.5%.