driver's compartment vs hackney cab

driver's compartment

noun
  • Synonym of cab (compartment at the front of a truck or train for the driver). 

hackney cab

noun
  • A motorised vehicle available for public hire; a black cab. 

  • A hackney carriage, a carriage pulled by a hackney horse, available for public hire. 

How often have the words driver's compartment and hackney cab occurred in a corpus of books? (source: Google Ngram Viewer )