TOKYO, Nov 1 (Reuters) - Tokyo's subway system, known for its punctuality, efficiency and at times overcrowded trains, will be tested when hundreds of thousands of foreign visitors descend on the Japanese capital for the 2020 Olympics, experts say.
Nearly 20 million people use public transport daily in the greater Tokyo area, home to more than 35 million people.
The games could draw 600,000 people to the city in late July and early August, typically the hottest time of the year, says the Ministry of Land, Infrastructure, Transport and Tourism.
Tokyo's subway system is already over capacity, raising fears of even worse congestion when Olympic visitors use the trains, especially during rush hour, said Azuma Taguchi, a Chuo University professor who has studied the issue.
A train carriage has a capacity of 143 to 162 passengers, according to the Japan railways website.
"At present you can be on a train with 200 percent of its capacity when it is at its worst," Taguchi told Reuters, warning that 300 percent capacity would cripple the subway system.
"However, there is a possibility that number could increase one and a half times during the Olympics," he said.
Some stations would fare worse than others. Shinjuku is already known as the world's busiest train station with 3.5 million passengers passing through each day.
Daily commuters like Yuki Sugiyama worry about how they will get to work when the Olympics kick off in two years time.
"I commute Monday to Friday, so if there is a big event on those days and it gets busy, the worst case scenario is that I won't be able to get on the trains," Sugiyama said.
The Tokyo 2020 Olympics run from July 24 to August 9, 2020, followed by a 12-day Paralympics that ends on Sept. 6.
Londoners had the same fears when they hosted the Olympics in 2012, but companies helped by encouraging their staff not to use public transport during the games.
However, in Japan's work culture, where employees are expected to show up for regular hours even in bad weather, there may not be as much flexibility.
For example, office workers often wait until the last minute to leave the office ahead of a typhoon, creating mass congestion at stations and on train platforms.
Thousands of commuters were stranded for hours outside Shinjuku station last month when Typhoon Trami forced authorities to close train lines to check for fallen debris.
The Tokyo government introduced a scheme last year called "Jisa-Biz", translated as "time difference commute", which they hope will help alleviate the problem.
The plan encourages firms to adjust employee work hours and open satellite offices away from busy areas. More than 840 firms have joined the scheme, including telecoms firm NTT East.
Kazumi Hasegawa, a 42-year-old NTT East employee, works from a satellite office a few days a month, avoiding a 50-minute commute to his main workplace. He said a change in work culture was needed for the scheme to succeed during the Olympics.
"It's important to work on it now, to improve the environment and change our mindsets so that we can deal with things such as the Olympics," he said. (Reporting by Yuiko Shiozawa and Mayuko Ono; writing by Jack Tarrant; editing by Darren Schuettler)