  Every human likes choices. But today's fast route planning algorithms usually
compute just a single route between source and target. There are beginnings to
compute alternative routes, but this topic has not been studied thoroughly.
Often, the aspect of meaningful alternative routes is neglected from a human
point of view. We fill in this gap by suggesting mathematical definitions for
such routes. As a second contribution we propose heuristics to compute them, as
this is NP-hard in general.
