Emblazoned with a tiger and a bear -- the mascots of the 2018 Winter Olympics and Paralympics -- a blue and white high-speed train rolled out of Seoul station Friday as a new line to the venues opened to the public.

The railway cuts travel times significantly, reaching Jinbu -- the station for snow sports at the Pyeongchang Games -- in one hour and 20 minutes from Seoul, and another 16 minutes to Gangneung on the east coast, where ice events will take place.

During the Games 51 trains will operate a day on the 278-kilometre line, which starts from Incheon airport southwest of the capital, with a total capacity of 20,910 passengers. The new railway is part of South Korea's KTX network.

Previously travellers from Seoul to Pyeongchang have mostly had to go by road -- around a three hour drive.

Many other Olympics and major sporting events have had trouble preparing infrastructure, with dashes to complete stadiums and other facilities in time, but in South Korea the process has been highly competent.

On Thursday, marking 50 days to go before the opening ceremony, the Games' chief organiser Lee Hee-beom said: "We are very proud of what we have created in Pyeongchang and the efficiency with which the venues and infrastructure have been built.

"We have worked hard over the last seven years to make our dream a reality and now the international sports festival is within reach for us all."

Even so the Games remain overshadowed by tensions with the nuclear-armed North, and the Russian national team has been banned over accusations of state-sponsored doping.

"The Olympics is a big event and if an international problem happens it will worry many people," Seoul resident Ahn Ju-young said at the station Friday before boarding the train.

"As a South Korean, I really hope there aren't any problems," she added.

Ticket sales have picked up, with 586,300 tickets sold as of December 10 -- the latest figures available from the organisers -- or 49.7 percent of the total 1.18 million available.

Another passenger, Kang Jae-Hoon, had no plans to go to the Games himself but hoped many people would use the new train line.

He regularly goes to Gangneung to surf, he said, but transport "has always been difficult".