LET ‘EM PLAY.

Children love adventure and activity.  Frame a vacation as adventure, slow down, and give them plenty of ways to burn their energy and focus their attention.  These are aspects of travel that children crave.  

I suggest doubling in your mind, the time that you think it will take to get from one point to another.  Then be pleasantly surprised when it takes less.  

Your vacation will be all the better for it.