I'm pretty uneducated on the subject, but I think if you were to include the alternatives the math becomes clear. It's not like transit is a secluded decision, if you don't build transit you end up with strained roadways which results in lost productivity, more expensive goods transportation, negative externalities (pollution, unhappy citizens) and then you layer on top how expensive roadway construction can be. Most of the roads stuff falls on the city, but fixing Deerfoot is pricy and the province is dragging it's feet on that as well.