  We consider the geodesic equation in impulsive pp-wave space-times in Rosen
form, where the metric is of Lipschitz regularity. We prove that the geodesics
(in the sense of Caratheodory) are actually continuously differentiable,
thereby rigorously justifying the $C^1$-matching procedure which has been used
in the literature to explicitly derive the geodesics in space-times of this
form.
