SHANGHAI, Jan 24 (AP) -- Alongside food and fire crackers, Chinese are adding a new item to their lunar New Year shopping: Adult diapers.

Sales have soared ahead of the holiday as travelers prepare for long trips home aboard trains so crowded that even the toilets are jammed with people, newspapers said Tuesday.

In Foshan, a southern industrial city with a large migrant population, supermarkets report diaper sales have risen 50 percent since the main travel season began on Jan. 14, the papers said.

The problem arises from the need to sell twice as many tickets as there are train seats to accommodate the crush of travelers. Those without seats must find some place -- any place -- to put themselves, including in overhead racks, between cars, and in the usually stinking toilets.

Just purchasing a ticket can mean lining up for hours.

Chinese make around 2 billion train journeys during the 40 days around the holiday, which this year falls on Jan. 29. Trains carry around 4 million people per day over the period.

"The deep seated concept of a reunion with families ... prompts people to repeat the journeys, even though they know clearly how difficult the journeys are," psychologist Pan Hong was quoted as telling China Daily.