THE IMPACT OF PUBLIC TRANSPORT PERFORMANCE IMPROVEMENTS ON SUSTAINABLE URBAN MOBILITY - AN EXAMPLE OF THE CITY OF ZAGREB

The global urbanisation process in the world is considering urban mobility as its top priority. Therefore, the public transport becomes more significant because of its spatial, energetic, economic and environmental advantages over other modes of transport and thus becomes the framework of sustainable mobility in most cities. Furthermore, the strengthening of public transportation in urban areas produces additional requirements in terms of its efficiency and operability. This is especially related to public surface transport (trams and buses) which is not segregated from other traffic, so the public transport process is constantly interfering with other vehicles sharing the same urban network. Consequently, this influence of other vehicles leads to commercial speed reductions in public transport and thus the attractiveness of public transport becomes significantly lower. The previous research on this subject has concluded that the yellow lane enforcement (as part of public transport priority by legislation) can lead to better transport process (travel times, network occupancy, and reliability) and other positive effects (energy savings, impact on the environment, reduction of external costs) at the entire urban network. This paper presents an analysis of priority by legislation for the entire tram network in the City of Zagreb the main attention is dedicated to yellow lane contravention in the peak hour. The analysis of the research conducted in this paper, related to operational features and shared space characteristics, provided conclusions regarding the significance of interferences and possible improvements in both efficiency and effectiveness of tram network in the City of Zagreb.