Possible reimagination of lost Montreal STM lines, Ligne 5 extensions
 

Even though this is technically my second post, I'm still more or less a new user here.

Nonetheless, I have a rather... interesting but hopefully feasible (at least logically) idea for an expansion the metro for the town I live in, Montreal. While I'm definitely on board with the REM network and finally making Eduoard Montpetit live to its original purpose, I've also been wondering about what will happen once REM starts working and bringing in more people.

Specifically this idea

What if we could resurrect the 4 major lost metro lines, (3, 6, 7, and 8) and use them as essentially supplementary lines for REM and parts of the existing metro where it's the busiest? All of them would be built as they had initially been planned, and aside from energy efficiency upgrades - namely lighting, the stations would also be built exactly as they had been planned initially. Of course, this would mean some stations would become transfer stations; nonetheless I would imagine that this could definitely make things easier.

Additionally, in addition to all of this, I've also re-imagined expanding the Blue Line/Ligne 5 from Snowdon to PE Trudeau Airport. While the REM branch there would remain, the Blue Line would essentially act as more of a 'local' line of train that would be used more during the daylight/evening hours when Metro is normally operating, as well as providing more direct service to the East end of the island along with Laval and places north. Then during the night or when the Metro is normally closed, REM could take over the duties until the Metro opened again.

Additionally, what would make these lines unique compared to the current stuff we have (besides the wheels, which could possibly be shared between each other to save money) is the way construction (and maintenance) of them is funded. Rather than be funded mostly by taxes, etc., 3, 6, 7, 8, and the 5 airport extension would be also funded by the major destinations around them. (3 would be funded by downtown events near the south end - especially stuff like Centre Bell, 6 would be funded by northeast end events, 7 and 8 by events at Parc Olympique, and the 5 airport extension by the airport - particularly related to stuff involving international flights). Of course, taxes would also be involved, but I think by having other sources for money be used besides taxes I think these projects could potentially gain a lot more traction than when they were initially proposed.

Also P.S. Line 6 would be colored 'Brown' but have a maroonish color similar to Qatar's flag, and the Mascouche line would be eliminated; the tracks would however remain and be used by Line 6)