A rail fastener includes a rail plate, a pad of elastomeric material between the plate and a support structure, a pair of clips for resiliently clamping the rail to the rail plate. The rail plate includes a pair of channels in which the clips occupy a first portion. The pad of elastomeric material preferably includes a pair of bosses dimensioned to be received within the unoccupied portion of the channel. The pad of elastomeric material is constrained from creeping out from underneath the rail plate whenever the bosses contact the end portions of the clips or the walls of the channel. The bosses are preferably noncompressable elastomeric material.