Are there any kind of vehicles that are some sort of combination of trams and trolleybuses?

Are there any kind of vehicles that are some sort of combination of trams and trolleybuses?
Yes, there are: Bombardier Guided Light Transit in Nancy, France -it's a dual mode vehicle, combination of Tram and Trolleybus. Whenthey are in "Tram mode", the vehicle follows a central rail (justlike a rubber tyred Tram), but the rail does not support thevehicle, or the actual wheels, which are as independent as those ofa Trolleybus. GLT vehicles have a steering wheel, though it is notused when following a guidance rail, and are capable of operatingindependent of the guideway, just like a Trolleybus. Instead ofpantograph, the vehicles collect their power from dual trolleypoles (enabling the vehicle to move sideways when they are in"Trolleybus mode").