by D.S. Lewith
With REM having taken over the existing Mount Royal Tunnel, Gare Centrale will be reduced to a stub end station for Via Rail and Exo. This impedes Via Rail's plans for the Montreal-Quebec City segment of their High Frequency Corridor as it would have used the Mount Royal Tunnel. However, Via Rail, in tandem with Exo, can construct a new Mount Royal Tunnel, this time connecting to the existing Saint-Jérôme line at Parc station. Like the Mount Royal Tunnel (historically), it would be at 25 kV 60 Hz AC but it would have a taller clearance gauge of 6 meters (around 19 feet), so as to enable the use of high-level rolling stock like Stadler KISS trains and Bombardier Bi-Level cars. While this would help with Via Rail's plans for the HFC, it would be also the start for Exo to transition to a through-running RER-style service to compliment REM (this also includes rebuilding Gare Centrale to a Spanish Solution configuration).
Upon completion of Exo RER, it would be organized in four lines
* Via Rail Corridor: Combines the Vaudreuil–Hudson line and new Mascouche line. It also includes a new branch line to Coteau.
* North-South Corridor: Combines the Candiac line with the old Mascouche line. The existing Candiac line will be extended to Sain-Jean-Sur-Richelieu and Iberville, and it includes a branch to Coteau (connecting with the Via Rail Corridor line), which in turn includes a branch to Salaberry-de-Valleyfield
* East-West Corridor: Combines two new lines: the Aéroport-Mirabel line and the Marieville line. The Aéroport-Mirabel line branches off from the Saint-Jérôme past Sainte-Thérèse, connecting to a station underneath Mirabel Airport. REM's Deux-Montagnes line will also be extended to Mirabel Airport. The Marieville line serves the cities of Chambly and Marieville, and it reactivates a disused rail line. The line also has a branch that goes to Candiac
* Northern Corridor: Combines the Saint-Jérôme and the Mont-Saint-Hilaire line. The Mont-Saint-Hilaire line will be extended to Saint-Hyacinthe, and will have a new branch serving Verchères.
This through-running, however, would come at the expense of the Lucien-L'allier station. However, the approaching tracks can be remade into HSR tracks for a new station right underneath Gare Centrale. There's enough underground space so as not to conflict with the metro trains
Upon completion of Exo RER, it would be organized in four lines
* Via Rail Corridor: Combines the Vaudreuil–Hudson line and new Mascouche line. It also includes a new branch line to Coteau.
* North-South Corridor: Combines the Candiac line with the old Mascouche line. The existing Candiac line will be extended to Sain-Jean-Sur-Richelieu and Iberville, and it includes a branch to Coteau (connecting with the Via Rail Corridor line), which in turn includes a branch to Salaberry-de-Valleyfield
* East-West Corridor: Combines two new lines: the Aéroport-Mirabel line and the Marieville line. The Aéroport-Mirabel line branches off from the Saint-Jérôme past Sainte-Thérèse, connecting to a station underneath Mirabel Airport. REM's Deux-Montagnes line will also be extended to Mirabel Airport. The Marieville line serves the cities of Chambly and Marieville, and it reactivates a disused rail line. The line also has a branch that goes to Candiac
* Northern Corridor: Combines the Saint-Jérôme and the Mont-Saint-Hilaire line. The Mont-Saint-Hilaire line will be extended to Saint-Hyacinthe, and will have a new branch serving Verchères.
This through-running, however, would come at the expense of the Lucien-L'allier station. However, the approaching tracks can be remade into HSR tracks for a new station right underneath Gare Centrale. There's enough underground space so as not to conflict with the metro trains
