parking lot vs rush hour

parking lot

noun
  • A road blocked by stop-start traffic. 

  • An open area, generally paved, where automobiles may be left when not in use. 

rush hour

noun
  • The times of the day when traffic jams are commonplace, due mainly to people commuting to or from work. 

How often have the words parking lot and rush hour occurred in a corpus of books? (source: Google Ngram Viewer )