The figure eight track is a simple structure made of 255 TJI Joists, 16 feet long, 2'-0" O.C. along the outside radius, supported by a series of composite 2"x4" and 2"x6" uprights and floor ties to accommodate 2-4'x8' sheets of 5/8" plywood cut in pie shaped sections. The over/under structure is a bridge spanning 18 feet across the track. Additional 1"x4"s are used throughout as diagonal bracing, cross strapping to secure the track surface and railing members. The 2"x4" vertical uprights are extended above the track surface to make the railing supports and top rails..