a traction weight system comprised of a plurality of generally rectangular cast metal plates sized so as to be arranged in a variety of two dimensional arrays to comport with the dimensions of different vehicle cargo compartments , each plate having means to interlock that plate with those adjacent plates along or across their closely confronting edges . the plates may be interlocked by various means , including integral tongue and groove structures formed in each plate , or a series of aligned notches which may receive coupling pins . each plate preferably has a height dimension substantially less than its width or length dimensions , so that the plates may be arranged across the floor or bed of the cargo compartment without interfering with the normal uses of that cargo compartment for storing or transporting cargo .