Here's an interesting article via the Shanghai Daily, "<a href="http://www.shanghaidaily.com/art/2006/07/01/284818/Fare_boxes_help_cheats_take_buses_for_a_ride__drivers_say.htm" title="Shanghai Daily">Fare boxes help cheats take buses for a ride, drivers say</a>":

<quote>Shanghai has 18,000 numbered buses serving 933 routes. Most buses use fare collection boxes in which passengers put fare money beside the driver. The box is transparent but drivers say it is difficult to see what passengers are putting in, especially at peak hours.

Huang said that some passengers would tear a 10-yuan-note in half, quickly use one half and then ask passengers for change.

Zhao Jun, a driver of the No. 933 bus, said: "If there is no conductor in the bus, it is very difficult for a driver to confront people found to be cheating."

Drivers also said fare boxes slowed down passenger flow.

Because the box is beside the driver, passengers can only get on the bus at the front, while previously, they could enter the bus through both doors. </quote>

This brings up two interesting issues.  Since buses do not give change, I occasionally see people resorting to the method described above.  However, I've never seen it done on a crowded bus.  The other issue is more interesting, and that is that both the drivers and the bus companies consider the fare box to be a <em>step back</em> from using human ticket sellers to sell tickets.  In an article I linked to <a href="http://www.ugcs.net/~takoyaki/archive/200505.html#p13" title="China, Shanghai, Books: Public Transportation">a long time ago</a>, it was mentioned that several lines were being down-<em>(or up?)</em>-graded away from the fare box because they did not meet size requirements for installing them.  Now even larger buses are asking to switch back to the human ticket seller.  That's interesting development, and a piece of 人性化 that I'll be happy to see return to the city.