hit the road vs start out

hit the road

verb
  • To begin traveling in an automobile or other road vehicle. 

  • To leave a place; to go away. 

start out

verb
  • To begin. 

  • To emerge suddenly; to jump out. 

  • To be or become conspicuous; to stand out. 

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