An end treatment array for crash attenuation includes a transition barrier module formed of side walls, end walls, a top wall, and a bottom wall, wherein the module walls together define an enclosed interior space. The end treatment array further includes a containment impact sled having an axially extending frame. The frame has a width sufficient to contain the transition barrier module within the frame when in an assembled configuration, and has an axial length which is at least one-half the length of the transition barrier module. The frame defines an interior volume, the purpose of which is to contain a substantial portion of the transition barrier module in the assembled configuration, and to contain debris caused by destruction of the plastic barrier modules in a vehicular impact. The containment impact sled is attached to the transition barrier module.