In this paper, the extension of the FASTSIM algorithm to a SDEC region is implemented and a strategy is proposed to generalise this algorithm to any general non-elliptic contact patch. The extended FASTSIM is applied to the prediction of wheel wear and rolling contact fatigue under typical non-Hertzian wheel/rail contact conditions, using CONTACT as a reference and showing that the extended version of FASTSIM proposed in this work provides more accurate solutions for non-Hertzian contact conditions, compared to other widely used formulations of FASTISM.