  The Noether gauge symmetries of geodesic Lagrangian for the pp-wave
spacetimes are determined in each of the Noether gauge symmetry classes of the
pp-wave spacetimes. It is shown that a type N pp-wave spacetime can admit at
most three Noether gauge symmetry, and furthermore the number of Noether gauge
symmetries turn out to be four, five, six, seven and eight. We found that all
conformally flat plane wave spacetimes admit the maximal, i.e. ten, Noether
gauge symmetry. Also it is found that if the pp-wave spacetime is
non-conformally flat plane wave, then the number of Noether gauge symmetry is
nine or ten. By means of the obtained Noether constants the search of the exact
solutions of the geodesic equations for the pp-wave spacetimes is considered
and we found new exact solutions of the geodesic equations in some special
Noether gauge symmetry classes.
