Passengers walk in front of Beijing Station July 11, 2007. [newsphoto]

Since July 1 when the summer peak season began, daily passenger transport volume has averaged 4.01 million and remained at a high level, with a record of 4.33 million on July 14, said Wang Yongping, spokesman with the ministry.

From July 12 to 16, the daily passenger transport volume exceeded 4 million for five consecutive days, four of which saw a daily volume of more than 4.2 million.

Students and holidaymakers contributed significantly to the robust transport, Wang said.

As an indicator of the peak season, standing-room-only tickets have begun to be sold for some bullet trains, those serving shorter-distance journeys in particular, including the Beijing-Tianjin and Beijing-Shijiazhuang lines.

Some bullet trains provide stools for passengers holding standing-room-only tickets, which cost the same as those for second-class seats, according to a report by the Beijing Morning Post.