I have successfully used CherryPy with a route manager under OS X.
The error you indicated is:
ImportError: No module named routes
This is pretty clear - Python cannot find modules routes. Did you install it? This is not part of CherryPy, it is a separate module that you will need to install. If you are using MacPorts, you should be able to:
port install py-routes
( py25-routes py26-routes , Python ). virtualenv, :
easy_install routes