In free market conditions, if public passenger transport services are commercially unprofitable, there will be no interest for transport companies to perform them. However, directly because of the citizens’ interests, on the one hand, and indirectly because of the economy, passenger public transport services have become of a general public interest. The authorities must prepare appropriate legal fair market conditions, based on which public transport will be subsidized and conducted. In order to achieve that, for the mutual benefit of the public, users and transport companies, it is necessary that the right Public Service Obligation Model (PSO model or in some literature PCS—Public Service Compensation) be defined. Within this study, the optimal approach to assigning a PSC contract to transport companies for performing the PSO in integrated and regular public passenger transport systems is determined. A novel model, presented in this paper, can help national, regional and local authorities to choose and determine the way and level of PSCs for conducting the public transport of passengers and establishing a sustainable public passenger transport system.

This paper has, for the purpose of setting sustainable cycling mobility, identified and assessed basic risk factors influencing crash severity. The study has examined risk factors for cyclist injuries and fatalities, according to the characteristics relative to cyclists, roads, vehicles and environment posing the risk of cyclist fatalities or serious injuries. The method of Binary logistic regression has been used as the study to analyze a sample of 21,235 traffic crashes involving cyclists in Serbia, over the period 2010–2021. The task was not to define the equations for risk prediction, but to determine the injury and fatality risk factors for cyclists. The results of this study show that cyclists older than 60 have a higher probability of being injured. Cyclists are more likely to be injured or killed on weekdays than on weekends, as well as in conditions of twilight. The odds of fatality and injury outside built-up areas are higher, while the odds of sustaining a serious injury are higher in built-up areas. The results of this study indicate significant overlapping with the previous research related to the analysis of factors influencing the severity of cyclist crashes. These results can be important for the policy makers and stakeholders involved, as they can help them gain clear understanding of the current road safety situation, for the purpose of creating an opportunity for developing best action plans and practical measures in the process of implementing sustainable urban mobility planning.

This research focuses on heavy-duty vehicles intended to transport compressed natural gases, i.e., class-2 dangerous goods. The analysis includes heavy-duty vehicles powered by diesel and compressed natural gas and trailers with two body types. The body types used in the research are battery bodies and multiple-element gas containers, with pressure vessels made of composite materials (Type-4) and steel (Type-1). The paper presents the methodological procedure for predicting fuel and exhaust gas emission costs as a function of fuel consumption and transported gas quantities. The effects of different types of bodies and different types of fuel on the transported quantities of gas, vehicle mass utilization, fuel consumption, and exhaust gas emissions are shown. The obtained results show that bodies with Type-4 pressure vessels transport 44% more gas than bodies with Type-1 pressure vessels for one turn. The most cost-effective solution for emission costs is diesel-powered, newer-technology vehicles and Type-4 vessels, requiring EUR 2.82 per ton of gas. Similarly, the most economical choice for fuel costs is compressed natural-gas-powered vehicles with Type-4 bodies and a cost of EUR 19.77 per ton of gas. The research results’ practical application pertains to the selection procedures of vehicles and bodies intended for the transport of gases; they should be considered in the decision-making process, with the aim of attaining a sustainable transport sector with lower costs and less impact on the environment.