commuter rail vs telpher

commuter rail

noun
  • A rail transport system with trains used to transport commuters between two places, typically their homes and works, normally within a metropolitan area and its surrounding environs, and generally distinguished from other rail transport systems (i.e. subways, metros, tramways) by having less frequent service, lacking free transfers between trains and using heavy rolling stock running on a mainline railway 

telpher

noun
  • An electric-run cable car used for transportation, along overhead wires. 

  • A system of transportation using telphers. 

verb
  • To transport with a telpher. 

How often have the words commuter rail and telpher occurred in a corpus of books? (source: Google Ngram Viewer )