What does "Average Miles per Day" mean under the Route Options, and how do I change it?

Average Miles per Day is the maximum number of miles that you would like to drive per day between stops. AdventureGenie will automatically add GenieStops to ensure that the driving distance between stops does not exceed the specified miles.  Important note: for changes to the "Average Miles per Day" to take effect, you MUST press the small "Recalculate Route" button (I.e., two arrows in a circle) after entering new information under "Routing Options."