Sales of adult diapers in China are soaring as the lunar New Year holiday approaches. Long trips and traveling aboard trains are so crowded that even the toilets are inaccessible.

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, local media reports.

In the middle of a busy traveling season, stations are selling twice as many tickets as there are train seats. Those without seats find somewhere to sit including overhead racks, between cars, and in the usually stinking toilets.

This year, Chinese travelers will make around 2 billion plane, train, ship and automobile journeys during the 40 days around the holiday, which this year falls on Jan. 29. Trains carry around 4 million people per day over that period, according to the Associated Press.