The story of a Taipei tourist shunned in July by more than 20 taxi drivers during rush hour in Xi'an has aroused heated debate on the city's transport problems. While it may seem to be an extreme example, the phenomenon is not uncommon in most cities.

Even when Bejing is crawling with taxis, it used to take Zhang Xiaowen, an office worker, almost half an hour to hail one at 7 am.

The difficulty in hailing a cab has seen a surge in the number of taxi apps.