United Airlines plans new family seating policy

How it works: A new seat-map feature "dynamically finds available adjacent seats at the time of booking," the airline's release says.

• "The online seat engine first reviews all available free Economy seats and then opens complimentary upgrades to available Preferred Seats."
• The policy will let travelers switch to another flight to the same destination without paying a difference in fare if adjacent seats are not available.

The change, which is being phased in now, will be complete by early March.