The wall is really nice... my only comment is that the sand features are a little to flat... the background needs a touch more depth.
I think you captured a theme of Kino no Tabi well though ^_^ It is a lonely road (even if her motorbike talks to her) but she doesn't belong anywhere. Everywhere she goes has their own traditions and beliefs and an outsider never really fits in... plus she wants to see everything... So yeah...