Many coasters incorporate a single helix into their layout.
Coasters can be categorised based on the position of this helix, relative to an observer facing the front of the station. The left and right layouts refer to a single helix on the left-hand side or right-hand side of the coaster respectively. A middle helix refers to a single helix placed in the centre of the ride, relative to an observer facing the station. The back layout refers to a single helix set back from the station, often separated from it by a lift hill.