The Use Zone is the ground level area beneath and immediately adjacent to a play structure or play equipment that is designated by ASTM F 1487 for unrestricted circulation around the play equipment and where it is predicted that a user would land when falling from or exiting the play equipment.
play routes are located within the use zone, accessible ground surfaces
must also be impact attenuating and meet ASTM F 1292-99 (1999 edition or 2004
edition) Standard Specification for Impact Attenuation of Surface Systems
Under and Around Playground Equipment.