The Belgrade trolleybus system forms part of the public transportation network in the city of Belgrade, the capital of Serbia. It is operated by the city-owned public transportation company GSP Belgrade. In 2017, the network consisted of 7 lines, with 125 trolleybuses operating on 55.8 km (34.7 mi) of two-way overhead wires. Trola, Serbian name for the trolley pole, became among Belgraders the common, colloquial name for the trolleybus in general.