In 2014 I started building a small HO scale trolley layout. It consisted of two 80cm x 160cm (approx. 30 x 60 in) sections. The second one got a small extension on one side. I used atlas code 83 track and flextrack and tried to incorporate some typical trolley/streetcar features, like a carbarn, a loop, middle of the street stub end and a small freight house. The layout had an outer and inner loop, to have some operational freedom.
Here are some pictures from the building process:
The layout was operated in DC and was based on a block system, so multiple trolleys could be operated at the same time. Equipment wise I had two PCCs (Baltimore Transportation Company from ConCor and Pittsburgh Railways from Bowser). In addition, there was a Red Arrow Brill Car from Bowser, as well as a Bachmann Spectrum Peter Witt (Philadelphia). I also had small two axle Straßenbahn from my hometown Remscheid, Germany, built from a kit.
The layout also included working (but manually operated) signals and lighting for night operation:
There was also some freight operation: