This article provides research findings on the impact of changes in the organization of trolleybus line No. 29 on passengers’ travel behaviour, in particular the inhabitants of Fikakowo residential district in Gdynia. The article comprises the following sections: introduction, characteristics of line No. 29 and transport infrastructure and rolling stock in operation, presentation of the results of own studies and conclusion. In the article secondary sources were used (overview of literature and the organizer’s internal materials) as well as the primary sources (results of own research conducted under method of face-to-face, individual and standardized interviews).