It means different rolling stock, different technology (possibly). Optimizing the system to the needs, not building around a legacy standard which imposes arbitrary constraints.
What I don’t get is the feeling that Toronto subway standards based on technological constraints of 70 years ago as the be all and end all. The epitome of mass transit perfection.
Advocate for higher ultimate capacity sure. But don’t equate every attempt of innovation as counter to goals.
I was using the Toronto subway just as an example of a higher capacity system, not as the standards benchmark. For sure the new line can use new equipment type, and not be bound by the compatibility with the existing lines, if the new equipment works better.
The concern is the train size constraints imposed by the selected routing. Those constraints will be in place for any equipment type.