an energy absorbing terminal is described that is made up of a plurality of cells partially defined by cambered panels made of thermoplastic or another suitable material . the panels are supported upon rectangular frames . the cambered portion of the panels provides a predetermined point of flexure for each panel and , thus , allows for energy dissipation during a collision . the stiffness of the crash cushion may be varied by altering material thicknesses and diaphragm spacing . in operation , a vehicle colliding in an end - on manner with the upstream end of the energy absorbing terminal will cause each of the cambered panels to bend angularly at its point of flexure and , thus , cause the cells to collapse axially . the use of thermoplastic , such as polyethylene results in a reversible , self - restoring collapse for the terminal , meaning that the terminal is reusable after most collisions .