LEIRIA, Portugal - A group of four Portuguese self-driving fans embarked on Saturday a far-flung journey to the 2010 Shanghai World Expo to support the six-month world fair in China.

A seeing-off ceremony attended by Mayor Raul Castro was held at the Luis de Camoes park square in Portugal's central city of Leiria.

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With the theme "So far but so close," the expedition team set off at 13:00 Saturday local time (1400 GMT) on its journey of some 16,000 km, traveling across a total of 13 countries.

Riding in two sport utility vehicles (SUV) filled with daily necessities, the four will drive along the route taken by Italian traveler Marco Polo during his odyssey to China in the late 13th century.

They are scheduled to get to China's borders in the northwestern part of Xinjiang on May 24, and reach Shanghai by June 6 after a brief stay in Beijing, making it possible for them to celebrate the Portugal Pavilion Day.

Along the journey, they will update their accounts of the trip over the internet.

Gaspar, one of the four travelers, aged 54, told Xinhua that he likes driving in the wilderness, and loves Chinese culture, especially Chinese food such as dumplings.

It took him a long time to prepare for his China trip, including selecting most suitable route and equipment, refitting vehicle, seeking sponsorship and taking health tests, he said.

"Our decided route to China is low-carbon and environmental-friendly, just as our tires," he said, adding that they prepare to plant two pine trees in front of the Portugal pavilion as a witness to Portugal-China friendship.

Opened on Friday, the 2010 Shanghai World Expo has drawn participation of 189 countries and 57 international organizations. It is expected to attract about 70 million visitors from China and abroad.