boulevard vs level crossing

boulevard

noun
  • A broad, well-paved and landscaped thoroughfare. 

  • A strip of land between a street and sidewalk. 

  • The landscaping on the sides of a boulevard or other thoroughfare. 

level crossing

noun
  • An at-grade crossing between a railway line and an ordinary road, with rails and road at the same level. 

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