back up vs travel

back up

verb
  • To move backwards, especially for a vehicle to do so. 

  • For the non-striker to take a few steps down the pitch, in preparation to taking a run, just as the bowler bowls the ball. 

  • To copy (data) so that it can be restored if the main copy is lost. 

  • To undo one's actions. 

  • For a fielder to position himself behind the wicket (relative to a team-mate who is throwing the ball at the wicket) so as to stop the ball, and prevent overthrows. 

  • To fill up because of a backlog. 

  • To halt the flow or movement of something. 

  • To provide support or the promise of support to. 

  • To reconsider one's thoughts. 

  • To move a vehicle backwards. 

  • Coordinate terms: back away, back off, stand back 

travel

verb
  • To force to journey. 

  • To move illegally by walking or running without dribbling the ball. 

  • To travel throughout (a place). 

  • To pass from one place to another; to move or transmit 

  • To be on a journey, often for pleasure or business and with luggage; to go from one place to another. 

noun
  • An account of one's travels. 

  • The working motion of a piece of machinery; the length of a mechanical stroke. 

  • The activity or traffic along a route or through a given point. 

  • Distance that a keyboard's key moves vertically when depressed. 

  • The act of traveling; passage from place to place. 

  • A series of journeys. 

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