back road vs trackway

back road

noun
  • A secondary road, a little-used road, a road through rural areas sometimes used as an alternative to main roads. 

trackway

noun
  • Any of two or more narrow paths, of steel, smooth stone, or similar, laid in a public roadway otherwise formed of an inferior pavement, such as cobblestones, to provide an easy way for wheeled vehicles. 

  • A set of footprints left in soft ground by a human or animal, especially if fossilized. 

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