The Expo 2010 Shanghai has seen a stable increase in the number of visitors in the past few days, and organizers estimate travel peaks may appear later this month during the Mid-Autumn Festival and again in mid-October.

At the end of last month, the daily travel flow to the Expo witnessed a dramatic decrease and the number of daily visitors bottomed at about 200,000 on Aug 31, according to official figures.

However, nice weather conditions and fewer people to bump shoulders with have attracted more visitors to the Expo this month. The number of visitors reached 486,000 on Sept 11, a record high in the past two weeks.

"The experience is much better because the sunshine is not as strong as it was in July and August," said Wang Xin, who visited the Expo Garden twice in July and again this month. "The lineups are also shorter."

Some 51 million visitors have visited the Expo in the past four and a half months, according to official figures, and media reports said about 18 million tickets remained unused.

Organizers forecast 400,000 to 500,000 people may visit daily during the National Day holiday, which starts on Oct 1. The number may even reach 600,000 to 700,000 a day.

As the Expo will end on Oct 31, people who have not visited the Expo Garden may crowd in to take a final glimpse of the event.

"I've postponed my travel plans to the Expo several times for different reasons," said Liu Huagui, a resident in neighboring Anhui province. "I'll miss the event if I don't visit this or next month."

Because only peak day admission tickets can be used during the National Day holiday and the last seven days before the Expo closes, most standard day admission ticket holders may end up visiting the Expo in mid-October.

Expo organizers have shown confidence in dealing with high visitor volume after receiving more than 500,000 visitors in July and August in a single day.

"We've set up an emergency plan to deal with high visitor volume after we experienced some difficulties during the trial operation in April," said Chen Xianjing, deputy director general of the Bureau of Shanghai World Expo Coordination.

Facing a possible dramatic increase in the number of visitors, some people have considered giving up their chances to tour the Expo. "The experience is hard to guarantee when so many people crowd into such a small area," said Li Feng, a traveler from neighboring Zhejiang province.