The scene was a little chaotic at some bus stops during the rush hours yesterday as Beijing formally scrapped its decades-long paper monthly passes for public transport and replaced them with an automatic fare collection (AFC) system.

The nearly 1.5 million monthly pass users on the bus and the 200,000 on the metro now have to use palm-sized "smart" cards instead.

A bus rider uses her smart card to enter the bus yesterday

A passenger without a card may still buy a paper ticket to ride.

Passengers used to be allowed to enter any door of a bus, but now they are required to enter through the front door (or the middle door on buses with three doors) because that's where the AFC machine is usually installed. They must exit using the back door (or the front and back doors of a three-door bus).

And on the first day, some residents of this metropolis with more than 14 million people obviously could not get used to the slight but abrupt change.

More than 1,100 buses were added to the 84 busiest lines of the city to alleviate the pressure during the rush hours, said Li Xiaosong, deputy director of the Beijing Transportation Commission, as saying.