Hey! Wanted to give some feedback on just HKG MTR (and possibly feedback that can be generally applied to all rail mapping too):
1) Excessive +DIV points, Tuen Ma Line doesn't interface (i.e., concurrent) with any of the lines that would be marked as concurrent, including with TCL (it's fully separate and on a covered ROW), ERL (different floors through Hong Hom), ERL (different elevation through Tai Wai).
Perhaps generally, "concurrent" lines should just be for when there's reasonable expectations that different sets of tracks can be used.
TWL and ISL follow different paths between Admiralty and Central.
TKL and KTL west of Yau Tong don't have any crossovers, so the +DIV point is also unnecessary
I suppose AEL and TCL can stay as concurrent, even through they are independently quadtracked between Kowloon and Tsing Yi.
2) ERL Lok Ma Chau services run through to Admiralty.
3) Using the station codes might be easier than making OurOwnAbrLikThi:
https://en.wikipedia.org/wiki/List_of_MTR_stations. Each line also has their own 3-letter abbreviation too.
4) For Metro systems that are unlikely to change, I feel we should be more liberal with shaping points... The red line we used with highways is too generous for parallel, dense metro systems. It should follow and appreciate that systems run with (under/over) roads and try to follow them to some extent.
Cheers!