Here are some possibilities... there are other ways this could be done of course... which one do you prefer? I prefer option 4, but I'm not a daily user of these lines.
Option 1 - Millennium line goes to Douglas. Short shuttle between Columbia and Lougheed. Many transfers required if you want to go to/from New West.
Option 2 - Make Expo Line branch at Columbia. Run every 3rd Expo train up to Lougheed. Millennium Line trains only go to Douglas.
Option 3 - The same as Option 2, but named more closely to the existing system. The trains that will branch off of Expo to Lougheed are called Millennium Line. Trains that go east/west to Douglas are called Evergreen Line.
Option 4 - Make Millennium Line branch at Lougheed. Run every 3rd Millennium train down to Columbia.
Option 5 - same effect as Option 4, but we give the two routes different line names.
Option 6 - both Expo and Millennium send every 3rd or 4th train between Columbia and Lougheed, before turning back again.
Option 7 - the existing system, added on. Millennium Line seems to go everywhere, and is really just a duplicate label at every station except for Sapperton and Braid.
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