I have lived in the same place, with this same variably-overgrown wall sitting behind it, since the age of eleven. Since age fourteen, I had nebulous (read: excessively researched but un-implemented) plans to apply for permission to paint it, since the wall is technically public property.
Age sixteen, I had the epiphany that this ugly wall was in fact literal miles of blank canvas - more than I could ever fill myself - and thus a better idea might be to establish a process or organization through which other artists could take advantage of the wall.
So far, it is yet another endeavor shelved for 'when I have time.' I continue to think it would be a fantastic project to set up in the spring, execute in the summer, and appreciate in the fall.