• A trolleybus is an electric bus supplied by an overhead line circuit (mostly DC) through a collector system known as "trolley" (fig.1). The trolley is in contact with the airlines when the vehicle is in motion.

• Trolleybuses became useful in the promotion of public transport. Many cities call for the introduction of reduced or zero emission zones, for which trolleybuses are a perfect solution. At the same time, trolleybuses are popular due to the trend towards the development of hybrid and electric vehicles, which are considered the future of urban transport.

• This paper presents the recent achievements and the progress tendencies of the traction system of public urban electric vehicles (UEV) with reference to trolleybuses and tram cars.