There is a mobility device user on about every third public transit ride I take on urban buses or suburban bendy-buses in the Greater Toronto Area. Every subway ride I take seems to have at least one or more users. I haven't ridden enough of the new-style streetcars or double-decker buses to make an assessment.

I don't know if the greater usage is due to the greater number of available spaces, or if the greater number of available spaces is due to the greater usage. It may also be due to the sprawling nature of Toronto - it may be less convenient to just wheel over to your destination than it would be in Scotland (especially in deep snow), forcing more people to take transit.