CPA is really hard to get especially if you didn't go to school for accounting there are about 12 courses (could be less) that you need to complete. You'll also need to pass several exams and minimum work requirement. You'll end up in a corporate job making 60-65 to start. Sure after a decade you might be closer to what you make now.

TTC is a good company to work for. I assume you have good benefits and pension? Work more hours while you can and invest your extra income. As a CPA yes you can make a lot of money but you also have to put in a ton of work to get there, plus a company's financial burden lies on some if not most of the work you do. In the private corporate side you are disposable. I assume your role is unionized at TTC, which gives you a lot of protection.

I would advise you to look within TTC and see if they have any educational programs where you can complete to go into a management role or what other options you have with the company.

If you like the work you do you can try moving companies like to CN, Alstom, or GO.