I am currently in the process of mapping the rapid transit (metro) system in Shanghai, and I have a few questions:
At interchanges (where two lines meet), should there be separate nodes on each of the lines or should the lines be connected at one node, representing the interchange? I checked other cities such as Paris, they have it connected on one node, however there are some problems that come along with the Shanghai Metro:
Between some interchanges, there is a considerable distance (of 400m or more) between them. The platforms of each line are very far apart, but they are named the same and do have an interchange in between them. To represent them as one node connected would be inaccurate because the two lines are actually far apart.
There are interchanges between elevated lines and subway lines. I’m using bridge = yes and layer = 1 or more to represent that it is elevated. And since one is elevated and one is underground, wouldn’t it be somewhat inaccurate to have them connected on one node?