  We study the emergence and dynamics of pointer states in the motion of a
quantum test particle affected by collisional decoherence. These
environmentally distinguished states are shown to be exponentially localized
solitonic wave functions which evolve according to the classical equations of
motion. We explain their formation using the orthogonal unraveling of the
master equation, and we demonstrate that the statistical weights of the arising
mixture are given by projections of the initial state onto the pointer basis.
