Claire, this or the stuff below might help you: arcpy.featureClassToShapefile_conversion()
James (just working off the top of my head - I think this is correct - will have to check it out tomorrow and get back to you), you can select the Routes simply by adding "\\Routes" to the end of the layer name, i.e.:
then copy the selected routes to a new shapefile with:
routes = outNALayer + '\\Routes'
You may also want to look into arcpy.CopyRows_management as you are just interested in the table...