They could be incandescent but since Rhode Island is so small RIDOT might own them all. Just like how NGrid owns a good portion of freeway lights, which are usually owned and maintained by the DOT. There are still a number of incandescent ped signals in southeastern MA, but their traffic signals have been LED as long as I've been around. Some yellow lights around here are still incandescent but when they die it's LED time.
I see some really small controllers in Providence and East Providence (electro-mechanical??) but lately downtown Providence has been getting all of the signals, poles, and equipment replaced. Now the downtown areas are mainly black LED siemens signals with fancy cast poles and black mast arms. RIDOT owns the MH acorns in downtown Providence but any cobraheads are owned by NGrid and are on satin aluminum poles (or wooden, though all of downtown providence is pretty much underground when it comes to distribution.