How Build my route works
Open Build my route from your trip. It suggests a sensible order for your cities (anchored on gateways like airport hubs), scores the route into a plain-English label, and flags problems, long transfers, backtracking, too many bases, too few nights, before you commit.
Travel effort between cities
Each leg shows an estimated journey and an effort level, from easy hops to genuinely long transfers (ferries and 4-hour-plus journeys are called out). Estimates favour trains, which is how Italy is best crossed; the itinerary and trip check read the same data.
Editing and saving
Reorder freely, adjust nights per city, or move a city to 'maybe' to park it without deleting it, nothing is final until you hit Save route. If you edit the order after saving, the route is marked as needing a re-save before the itinerary builder unlocks, so your day-by-day is always built on the route you actually chose.