The transport sector, pivotal in sustaining economic activity and regional development, stands as a double-edged sword, enhancing competitiveness and mobility while posing substantial challenges to environmental sustainability. It remains heavily dependent on fossil fuels, characterized by inefficient infrastructure and scant emphasis on environmental stewardship. This trajectory not only undermines long-term viability but also exacerbates pollution levels, including greenhouse gases and air and noise pollutants, thus degrading environmental quality and posing health risks globally. Consequently, there is an imperative need for a paradigm shift towards sustainable transport practices. This study employs the Ranking Alternatives with Weights of Criterion (RAWEC) methodology to assess the sustainability of various transport modes within the European Union in 2020. Evaluation criteria included employment numbers, turnover, final energy consumption, greenhouse gas emissions, and transport-related fatalities. Criterion weight coefficients were calculated using the Standard Deviation Method, Entropy, and FANMA methods. The findings underscore the necessity for strategic adjustments in transportation planning and policy to align with sustainability objectives.

Road transport emerges as a crucial segment of the transportation system, demanding comprehensive analyses of operational performance across passenger and freight domains. This investigation delineates a meticulous multi-criteria analysis of Serbian passenger and freight road transport, relying on data extracted from the Annual Statistical Reports promulgated by the Statistical Office of the Republic of Serbia during 2015-2021. Initially, a compendium of eight pertinent criteria, namely carrying capacity, total number of passenger and tonne-kilometres, employee count, generating power, fuel consumption, and foreign currency receipts, is identified, with a subsequent emphasis placed on six criteria necessitating multi-criteria analysis, applicable cohesively to both passenger and freight transport sectors. Weighting coefficients for each criterion are calculated employing the entropy method, while a multi-criteria ranking of the operational performance of road transport is devised through the application of the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method. The quintessence of this research lies in the execution of a novel multi-criteria analysis with an aspiration to architect a hierarchy regarding the operational performance within the scrutinised timeframe of road transport in Serbia.

Public urban passenger transport is a large consumer of fossil fuels, which contributes to the emission of harmful gases. Although alternative fuels are more environmentally friendly, their widespread use is still challenging even for developed countries, partly due to their higher cost. There is also some resistance to introducing sustainable transport systems due to the perception that it could significantly change the style and quality of life. Today, the bus subsystem of public passenger transport is the most widely used public transport technology. Many European public transport systems rely heavily on buses powered by conventional fossil fuel, are integral to their local fleets in most EU states. For public urban transport to increase its participation in the modal distribution of trips in cities, public transport vehicles must comply with established European standards that define different limits of exhaust gas emissions. Public transportation of passengers by bus plays a significant role in the transport system of the City of Niš as an accessible and acceptable means of transportation. Buses that use electricity as propulsion (e-Bus) are considered the cleanest technologies, producing zero local emissions and having the greatest impact on increasing local air quality. In the paper, a multi-criteria ranking of six electric buses was performed based on four criteria, available on the market of the Republic of Serbia, using MABAC and MOORA methods, while Entropy method was used to calculate the weight coefficients, to select an adequate bus manufacturer for the needs of public passenger transportation in City of Niš.

Urban traffic significantly contributes to air pollution, and its effects are expected to increase in the coming years. Environmental policy measures can help achieve long-term goals, in which new modes of mobility for residents can play a significant role. However, local-level decision-making is also crucial. In the face of economic volatility, cities must carefully decide on sustainable transportation expenditures that respect budget limitations and promote local air quality standards. To create a sustainable traffic strategy and address the rise in traffic demands due to increased passenger transport, the use of buses with alternative drive technologies and fuel options is becoming increasingly important in European cities. However, buses utilizing alternative drive technologies and fuel options have varying impacts on air pollution, and the required investments and expenses vary. To determine the appropriate propulsion technology and fuel for buses specifically in Nis, the analysis based on multiple criteria will be conducted using the CRITIC (Criteria Importance Through Intercriteria Correlation) and in the following TOPSIS (Technique for Order Performance by Similarity to Ideal Solution) methods according to the defined criteria. The CRITIC method utilizes different normalization types to compute weighting coefficients and analyze their effect on the alternative rankings. Additionally, Spearman's rank correlation coefficient will be used to examine the degree of correlation between the rankings of different alternative drive technologies and fuel options for buses, calculated through the TOPSIS method.

The proper design and configuration of the swing drive mechanism of a hydraulic excavator are crucial to improve energy consumption and efficiency and ensure operational stability. This paper analyzes the influence of the relationship between the parameters of a hydraulic motor and a reducer, which form the integrated transmission of a swing drive, the dynamic characteristics of a hydraulic excavator on loading, and the dynamic stability of the drive. The analysis deals with an excavator model that has the same parameters of the kinematic chain members, the same parameters of the upper structure drive mechanisms, and two variants of the swing drive that, with different integrated transmission parameters, provide the upper structure with the identical number of revolutions and equal rotating moment. One swing drive variant possesses an integrated transmission with a hydraulic motor with a low specific flow and a reducer with a high transmission ratio, while the other drive variant has the opposite parameters. Understanding this relationship is essential for optimizing the design of excavators to achieve better performance and dynamic stability under varying operational conditions. As an example, this paper provides the analysis results regarding the influence of the relationship between the parameters of the integrated transmission hydraulic motor and reducer on the loading and dynamic stability of the swing drive in a tracked hydraulic excavator of 100,000 kg in mass and 4.4 m³ in loading bucket volume, as obtained from the developed dynamic mathematical models of the excavator using the MSC ADAMS program. The results indicate that the dynamic loads on the swing drive’s axial bearing are higher in the variant with a low-specific-flow motor and high transmission ratio reducer during the acceleration and deceleration phases. However, this configuration demonstrated better dynamic stability, with lower oscillation amplitudes and shorter damping times compared to the variant with a high-flow motor and low transmission ratio. Those findings provide valuable criteria for the optimal synthesis of swing drive mechanisms in large hydraulic excavators using multi-criteria optimization methods.