neutral ground vs toll road

neutral ground

noun
  • The median strip or central reservation between lanes of traffic in a divided highway. 

  • Used other than figuratively or idiomatically: see neutral, ground. 

toll road

noun
  • A road for the use of which a toll must be paid; a turnpike. 

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