The International Terminal is there to collect passengers from other train stations. Every time you collect profits from your train stations, the passengers from those stations get transferred to the International Terminal.

You can use international trains to send out passengers from the International Terminal to the cities of your friends, earning you additional income.

Upgrade the International Terminal to be able to handle more passengers and international trains. Upgrade your international trains to be able to send out more passengers, and get more money for each of the stops they make.

Have fun playing the game!