Some people love to stay a week in Melbourne. Though better to tell it where you want to start, what you like in the middle (waypoints, travel-thru) and where you finish. Could be same Melbourne or could be diff location.

We did not design UI at all, because we are thinking of voice interface. You are telling your desires and constraints in conversation. They are captured. Then API is called.

Or have dedicated "to" and "from" places, with the option to add more destinations.