This is why I have always thought the DRL should be a RER tunnel and not a subway.
Certainly build the DRL as planned with the same number of stations and frequency but use standard gauge with catenary. This way the system can be part of RER so electrfied RER trains can also use the tunnel. This allows for some 'relief' on Union station and fewer transfers for those not going right to the financial core. If RER is successful, trains could be arriving every 20 seconds in 20 years and that will put too much pressure on Union and a RER DRL tunnel would also allow for a back-up way into the city if for any reason there is n incident at Union.
By building standard gauge the system will also be vastly cheaper and easier to expand north of Eglinton as it can then make use of the already existing Richmond Hill GO corridor.
Building an "RER" tunnel before we have RER seems odd . . .
I'm fairly certain that past GO expansion plans have called for six or more tracks through here, but now this shortsighted limiting of the corridor to four for the sake of ramming the Ontario Line though will come back to bite us.
Only in North America would it be suggested that you need more than four tracks to handle the traffic on this corridor for decades, we don't need more tracks folks, we need better operations and planning.
It will be standard gauge with catenary, but its extremely likely that the tunnels will be too small to handle GO EMUs, not to mention it will probably be electrified with 1500V DC compared to 25kV AC on GO RER.
There's also no way you are gonna get regulatory approval so its a non starter . . . The OL trains will NOT be designed to handle collisions
I'm amazed that ML pushed the OL plan forward given their institutional emphasis on regional travel. I wonder how that ended up happening. It's telling that over the past three years, they've never addressed the concerns surrounding the impact of the OL on the capacity of RER
There is no reasonable concern, 4 tracks is plenty if we NEED more we can find other options . . . we don't even have catenary going up, lets get RER going before we start worrying that quad tracks aren't enough for the like 20 tph we might need? Like seriously folks, 2 tracks is enough for 30 tph . . .
Also ML didn't push the plan, the province made them in charge of the rt stuff . . . and the OL is much more integrated with GO than the DRL . . .