You make so many wild assumptions of things you don't know. You personally know for a fact that the TTC has never investigated this?
Perhaps they have but realized it was incapable or too costly just to eliminate a single transfer point.
Just because you've personally ridden on some other systems doesn't mean that it will work here.
There are tons of engineering problems with this that you are omitting.
This also comes down to a political faux pas called the sunk-costs fallacy and it is one that kills political careers.
Subways are deemed as a better level of transit than LRT's by the general public. And its somewhat true, the subway cars do hold more passengers than an LRT.
Imagine the outcry that would come when the public around the Sheppard Subway found out that after 15 years they were converting their heavy rail subway system to light rail LRT. A DOWNGRADE! (in the public eyes)
There would be an outcry of government waste, spending millions on a system that was only 15 years old to downgrade it to a lesser technology.
Seems like you said to yourself "let's throw a bunch of stuff and see what sticks".
No, I don't know that the TTC has never investigated this. However, they have never released any results of an investigation publicly or as part of board meetings documents. On his blog, Steve Munro has discussed the TTC looking into using the Sheppard line for LRT, but has only mentioned them considering changing the design of the existing stations, rather than considering a different rolling stock. If you have some time of insider knowledge that the TTC has indeed studied this, you should share!
Not Invented Here Syndrome isn't a complete argument. Tell me *why* a dual-mode rail vehicle (examples of which exist in New York, Boston, the UK, and The Netherlands) won't work in Toronto.
Please, let me know about these tons of engineering problems so that I can actually attempt to respond to them.
As far as I can tell, the sunk cost fallacy would suggest that it is a fallacy to not consider alternative solutions simply because so much money has been sunk into the subway-and-Transit City LRT status quo.
As for public opinion, it is indeed an unfortunate issue that for two types of rolling stock, delivering the same speed of operation, grade separation, and capacity, that one could be considered inferior because it is also capable of operating in a non-grade-separated environment. It is a legacy of the Ford era that we will have to continue to deal with. So I will agree that there is a political issue. In fact, I would argue that the only real issue is a political one. But I'd like to at least establish whether my idea is financially feasible before worrying about cynical public responses.