  This paper discusses some of the physical properties of plane symmetric
self-similar solutions of the first kind (i.e., homothetic solutions). We are
interested in calculating the expansion, the acceleration, the rotation, the
shear tensor, the shear invariant, and the expansion rate (given by
Raychaudhuri's equation). We check these properties both in co-moving and
non-co-moving coordinates (only in the radial direction). Further, the
singularity structure of such solutions will be explored. This analysis
provides some interesting features of self-similar solutions.
