To prevent serious traffic accidents by locating used pet bottles enclosed with reinforced plastic frames on roads as a buffer to alleviate violent impacts caused when cars collide.

Used pet bottles 3 are laid out on the lower stage 1 of a reinforced plastic frame, with their caps 4 tightly closed after they were filled up with water or left empty. When the lower stage 1 of the reinforced plastic frame was filled up with these pet bottles, strong adhesives are filled up on the surface 5 of lower stage 1, then the upper stage 2 of the reinforced plastic frame is placed on top of the lower stage 1, and then the two are completely adhered together. Several frame blocks prepared in this way are adhered laterally or in plies together according to the conditions of the site on a road where they are installed. By so doing, they are useful as a buffer system available for all roads in whatever conditions.