Trends in the development of trolleybus transport in Poland at the end of the second decade of the 21st century

Trolleybus transport played a changing role in Poland. Historically, these were both periods of dynamic development and rapid regression. The article analyzes the period from 2004 to 2018. An attempt was made to systematize and organize information on the development of trolleybus transport in this period. The available scientific literature as well as the economic, organizational and technological conditions for the functioning of trolleybus transport were analyzed. The analyzed period was undoubtedly a time of dynamic development of all three existing trolleybus systems in Poland. The structural funds of the European Union played a significant role in this, allowing to revitalize neglected and underinvested systems. At the same time, climate change has influenced global and local conditions in terms of the approach to transport in cities. Trolleybuses perfectly respond to the demands to reduce emissions from transport in cities. Also thanks to the development of battery technologies, trolleybuses have become more flexible in operation. The article compares the years 2004 and 2018, additionally illustrating the changes taking place on the maps.