People traveling to venues of the 2020 Tokyo Games at the same time as commuters are heading to work are expected to cause serious congestion at railway stations in the metropolitan area during morning rush hours, a researcher has warned.

Hub stations and those near games venues will be overcrowded unless spectators are diverted to less busy stations or measures are taken to have commuters avoid peak hours, Azuma Taguchi, a professor of traffic networks at the Faculty of Science and Engineering at Chuo University, pointed out in a recent study.

"There will be a need to promote staggered work hours or guide spectators to stations a little further from game venues," Taguchi said.