In my city, there is a tram network. The trams share the roads, but not entirely. There is one spot in particular where the tramlines bear left and the road bears right and someone driving onto the lines and getting stuck is a weekly occurrence. There are 13 no-entry signs, two signs that say 'tram only', and all kinds of paint on the road to guide cars in the right direction.
It still sometimes amazes me that by passing an arbitrary test these same people are allowed to pilot a heavy metal box around soft and squishy pedestrians.