A road vs autoroute

A road

noun
  • Any of many major roads in the United Kingdom, mostly multi-lane dual carriageways between cities 

autoroute

noun
  • An expressway in any Francophone country. 

  • An expressway, freeway, motorway or highway. 

How often have the words A road and autoroute occurred in a corpus of books? (source: Google Ngram Viewer )