Between miles-long trains and an e-commerce boom, cargo on freight trains has become easy pickings for robbers.

The Grand Super Cart sightseeing train was stopped 105 meters in the air on the Takachiho Iron Bridge—the highest railway bridge in all of Japan—on a recent day in mid-December. The ...

While on board, passengers enjoy panoramic glass ceilings that bring the outdoors into the train. Several cars also have outdoor viewing platforms for a breath of fresh air amid the scenic views.