text: Routes are outlined before departure time to select the shortest and most efficient route?
classes:  No, many routes are prepared ahead of schedule, although this does not affect flight performance or time.  Besides, many routes are prepared ahead of schedule, although this does not affect flight performance or time.  Yes, many routes are prepared ahead of schedule, although this does not affect flight performance or time.  Meanwhile, many routes are prepared ahead of schedule, although this does not affect flight performance or time.