To use modern high speed trains for all destinations, Jin can merely copy every other modern city subway train station blueprint. Not to mention, they were easy to find as well. Mainly because the System is able to get its hands on the latest designs from the databases.
Not to mention, it is efficient in terms of design which the System likes due to having people just go to whichever platform they need to go. Unlike the Waterloo train hub, people have to wait for the train to depart until it's out of sight then the next train will arrive.
For now, it's not too bad because of the number of service and dungeon instances that Dungeons and Pandas had but it would be a pain in the butt for Jin in the future if he were to add even more. Also, the System consistently creates new landscapes for the users to see under in the subway station, all they have to handle is the darkness of the tunnels.
