Yup, even a hundred year old tram system is popular and cheap in Hong Kong. It has no AC and it’s crowded, but it supplements very well the clean, modern, reliable subway. The MTR (Mass Transit Railway) of Hong Kong is a model for the world and is consistently great in service and profitability. http://en.wikipedia.org/wiki/MTR
I have had the pleasure of seeing these in real life, and it is amazing to watch them go down the narrow streets. It reminds me of Denver’s very old Tramway. Before Lightrail was even a thing, Denver had a great network of Trams. http://en.wikipedia.org/wiki/Denver_Tramway
But now Denver has http://en.wikipedia.org/wiki/Regional_Transportation_District RTD.