byway vs hard shoulder

byway

noun
  • a road that is not frequently travelled. 

  • a little-known or arcane field of study or detail. 

  • a road or track not following a main route; a minor road or path. 

hard shoulder

noun
  • A verge to the side of a highway, which should be used only in case of an emergency (especially on a motorway) 

How often have the words byway and hard shoulder occurred in a corpus of books? (source: Google Ngram Viewer )