Why can the silk road be described as a social system rather than simply as a transportation route?

It could be considered a social system because of the way it is organized. First of all, it might present cultural fusion, that is to say; religion, technology, etc are key elements for its functioning. Then, people who work in the trade road need a language. There can be found a misture of culture due to the amount of people working in this system. As regards religion, it might be said that the Silk Road helps to its expansion and spreading. 

from the conditions of the working class in england by friedrich engels,the main idea is :

manchester's leaders hoped to oppress its working class to benefit factory owners.