In answer to a query from a regular poster, ‘Zwei’ has found a picture of a Russian trolleybus and tram intersection showing the overhead. I have included from Wikipedia, a short description of tram/trolleybus junctions, locations, and the electric overhead.
Tram – Trolleybus Crossings
Trams draw their power from a single overhead wire at about 500 to 750 V, while trolleybuses draw their power from two overhead wires, at a similar voltage. Because of that, at least one of the trolleybus wires must be insulated from tram wires. This is usually solved by the trolleybus wires running continuously through the crossing, with the tram conductors a few centimetres lower. Close to the junction on each side, the wire merges into a solid bar running parallel to the trolleybus wires for about half a metre. Another bar similarly angled at its ends is hung between the trolleybus wires. This is electrically connected above to the tram wire. The tram’s pantograph bridges the gap between the different conductors, providing it with a continuous pickup.
Where the tram wire crosses, the trolleybus wires are protected by an inverted trough of insulating material extending 20 or 30 mm below.
Until 1946, there was a level crossing in Stockholm, Sweden between the railway south of Stockholm Central Station and a tramway line. The tramway operated on 600-700 V DC and the railway on 15 kV AC. Some crossings between tramway/light rail and railways are still extant in Germany. In Zurich, Switzerland the VBZ trolleybus line 32 has a level crossing with the 1200 V DC railway to mount Uetliberg; at many places in the town trolleybus lines cross the tramway. In the Swiss village of Suhr the WSB tramway operating at 1200 V DC crosses the SBB line at 15 kV AC. In some cities, trolleybuses and trams have shared the same positive (feed) wire. In such cases a normal trolleybus frog can be used.
Another system that has been used is to coincide section breaks with the crossing point so that the crossing is electrically dead.
Many cities had trams and fishsticks both using trolley pole current collection. They used insulated crossovers which required tram drivers to put the controller into neutral and coast through. Trolleybus drivers had to either lift off the accelerator or switch to auxiliary power.
In Melbourne, Victoria, tram drivers put the controller into neutral and coast through section insulators, indicated by insulator markings between the rails.
Melbourne has four level crossings between electrified suburban railways and tram lines. They have complex switching arrangements to separate the 1500 V DC overhead of the railway and the 650 V DC of the trams, called an overhead square. Proposals have been put forward which would see these crossings grade separated or the tram routes diverted.
In Athens, there are two crossings between tram and trolleybus wires, at Vas. Amalias Avenue and Vas. Olgas Avenue, and at Ardittou Street and Athanasiou Diakou Street. They use the above-mentioned solution.
From the opening of the tram system in the summer of 2004, trams and trolleybuses in the direction of Pagrati shared the same exclusive lane, about 400m long, on the far right side of Vas. Olgas Avenue, with tram and trolleybus wires side-by-side above a narrow lane of road. The trolleybus wires were on the far right of the lane, away from the trams’ (very wide) pantographs. Trolleybus drivers were required to drive very slowly because the trolley poles were extended to their limits. A change of route for trolleybuses was implemented in mid-2005, ending this arrangement.
In Milan most tramway lines cross the circular trolleybus line once or twice, so crossings between overhead tram and trolleybus wires are quite commonplace. Trolleybus and tram wires run parallel in some streets, like viale Stelvio and viale Tibaldi.