A high-density relax-transport system, intended especially to equip the useful space of means of transit and transport, fundamentally characterized by its arrangement in this space, in a compact interlocking structure, of a certain number of individual berths. These berths are formed of couchettes whose flexible and/or rigid bottoms have an at least transversally concave general shape and whose widths decrease advantageously toward the extremities, particularly from the hips to the feet. The said interlocking is so conceived that each couchette berth is limited to the functional volume required to permit the occupant''s movements, with a generous space allowance in the torso and head region.