$ is $ & trade is trade & a train is a train

So, here is the modern silk road. 

It is from Xian to Budapest:

http://news.xinhuanet.com/english/2017-04/01/c_136177214.htm.

Starting Nov. 28, 2013, Xi'an has launched 317 cargo trains to central Asia and Europe, exporting 474,000 tonnes of goods as of April 1 this year.

Do you honestly think the trains that return are empty?

Trade is a two-way affair.