Disclosed is a substitute ground surface material comprising a granular component comprising sand and at least one of clay or silt, wherein the granular component is treated with a binder comprising an interpolymer dissolved or dispersed in a non or low aromatic oil and wherein the binder is generally fluid at the treating conditions. In a process for treating existing dirt tracks or existing synthetic tracks, an aqueous emulsion of the interpolymer/oil bind is sprayed on the existing dirt track to form the substitute ground surface in-situ.
