dragway vs speedway

dragway

noun
  • A dragstrip, a place where drag races are held. A racetrack to drag on. 

speedway

noun
  • A racetrack venue designated especially for the sport of auto racing. 

  • A positive-camber banked oval racing circuit, designed for high speed cornering, racing anywhere on the length of the track. 

  • A road for high speed traffic; an expressway. 

  • A size of paved banked oval racetrack, smaller than superspeedways, but larger than a mile. 

  • A form of bicycle racing on flat (non-banked) oval dirt tracks. 

  • A form of motorcycle racing on flat (without camber) oval dirt tracks using motorcycles with neither brakes nor gears. 

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