The opening of an underwater railway tunnel in Turkey can shorten travel times between Europe and Asia and boost rail freight between the two continents, rail experts say.

"With the Marmaray tunnel opening and serving rail networks in Europe and Asia, journey times between the two continents will be shortened substantially," said Yang Hao, a professor at Beijing Jiaotong University who researches rail transport management.

"Routes operating through the tunnel will be shorter than existing ones running through Russia to connect China and Western Europe, providing more options for freight carriers."