An often overlooked feature of trams (or light rail) is that they routinely handle far steeper hills than what many buses can handle, making them perfect for places like Los Angeles, Montreal, SF (9.1%), Sheffield (10%), and of course the steepest of them all, Lisbon (13.9%). 
They also handle snow much better than busses, and if you were to combine snow and steep hills (looking at you Montreal!), trams are absolutely superior in terms of safety, speed, reliability. Here is a tram in Sapporo, Hokkaido, northern Japan.
Some trams carry their own snow plough, but in Sapporo special "Sasara" trams are used in winter. Easier and cheaper by far than to plough buss lanes. Not the eco friendly bamboo brushes!
Trams are electric and do not need heavy and incredibly wasteful batteries to operate. Few electric buses can handle steep hills and even ordinary buses have problems with bad weather. Trams used to run these streets with no problems (Montreal).
Trams are also by far the most energy and cost effective mode of transport in inner cities where frequent stops and traffic lights means constant acceleration and breaking. Their metal "tires" also contribute far less to city air pollution. medium.com/@blaisekelly/w…
They are by far the most robust public transport system, almost nothing can stop them. Even if completely disconnected from power and fuel, a tram system can easily be replaced by horse power. This is tricky with subways, trains, or buses.
Our ancestors built things to last, and with trams that means the older the tech the better it works. In Stockholm (Sweden) the latest 21st century super high tech light rail is dependent on being serviced by a special plough rail during snow weather. Built in 1904!
