NEWS REGARDING THE MANAGEMENT OF THE SUSTAINABLE DEVELOPMENT OF CAR TRANSPORTATION FROM THE PERSPECTIVE OF AUTONOMOUS VEHICLES

The scientific paper presents a practical research carried out by the authors in order to implement certain concepts of technical nature, so that those interested in this field can become aware of a certain way of exposing the problems regarding the role of technology and autonomous vehicles in the sustainable development of car transportation. According to previous research, it has been found that human error has a share of about 95% in the occurrence of road accidents in Europe, causing thousands of human lives to be taken away annually. Experts in the field say that autonomous vehicles can significantly reduce this percentage and at the same time contribute to increasing road safety. Digital technology also has its advantages and disadvantages. It helps reduce congestion and pollution in road traffic, increases access to mobility for people with disabilities, creates new jobs, brings economic growth, increases safety in road traffic but can also become dangerous when disturbances and malfunctions make their mark on artificial intelligence. We present further a technical and managerial study with engineering nuances, through which readers can look at and understand the concept of sustainable development in a global context, presenting the place, role and current stage of development of the autonomous vehicle in the road transport system. At the end, some conclusions and further research directions in the approached field are presented.

Use of hydrogen as a source of clean energy

The increase in energy consumption is closely correlated with the continuous evolution of human society, which implies both the depletion of fossil fuels and the increase in pollution levels. One solution to these problems is to obtain electricity from renewable sources but also to use alternative fuels for car transportation. Within the paper, there are presented the necessary conditions for the design of hydrogen gas stations in accordance with the legal requirements in force regarding the protection to explosion.

Experimental Assessment of Influence of the Ball Bearing Raceway Curvature Ratio on the Level of Vibration

Raceway curvature ratio is a very important parameter, because its values influence the performance characteristics of rolling-element bearings, their durability and the level of generated vibrations. However, the level of generated vibrations is one of the most important operating parameters of the rolling-element bearings. Excessive vibrations generated by rolling-element bearings affect the operation of the whole mechanism. The article presents experimental studies aimed at evaluation of influence of the inner and outer raceway curvature ratios of 6304-type rolling-element bearings on generated vibrations values. The raceway curvature ratio was determined based on results of metrological measurements. For this purpose, the radii of the inner and outer raceways as well as the diameters of the balls were measured. Design and principle of operation of an innovative system for analysis of the raceway geometry of the rolling bearing rings was presented. The vibration analysis was carried out in three frequency ranges, i.e. low (50-300 Hz), medium (300-1,800 Hz) and high (1,800-10,000 Hz). Values of measured vibrations were expressed in Anderon units. The test results showed that increase in the raceway curvature ratio causes a moderate decrease in the value of the generated vibrations. The research results presented in this article will serve as a guidance to designers and manufacturers of the rolling-element bearings on how to modify the geometry of raceways and balls to obtain bearings that generate low vibration values. That is very important in car transportation.

Flying Car Transportation System: Advances, Techniques, and Challenges

In order to fulfill transportation demands, people have well-explored ground, waterborne, and high-altitude spaces (HAS) for transportation purposes, as well as the underground space under cities (namely, subway systems). However, due to the increased burdens of population and urbanization in recent decades, huge pressures on public transportation and freight traffic are introduced to cities, plaguing the governors and constraining the development of economics. By observing the fact that near-ground space (NGS) has rarely been utilized, researchers and practitioners started to re-examine, propose and develop flying cars, which are not a totally novel idea, aiming at solving the traffic congestion problem and releasing the strains of cities. Flying cars completely differ from traditional grounded transportation systems, where automobiles/trains are suffering track limitations and are also different from the air flights in HAS for long-distance transfer. Therefore, while observing the lack of specific literature on flying cars and flying car transportation systems (FCTS), this paper is motivated to study the advances, techniques, and challenges of FCTS imposed by the inherent nature of NGS transportation and to devise useful proposals for facilitating the construction and commercialization of FCTS, as well as to facilitate the readers understanding of the incoming FCTS. We first introduce the increased requirements for transportation and address the advantages of flying cars. Next, a brief overview of the developing history of flying cars is presented in view of both timeline and technique categories. Then, we discuss and compare the state of the art in the design of flying cars, including take-off \& landing (TOL) modes, pilot modes, operation modes, and power types, which are respectively related to the adaptability, flexibility & comfort, stability & complexity, environmental friendliness of flying cars. Additionally, since large-scale operations of flying cars can improve the aforementioned transportation problem, we also introduce the designs of FCTS, including path and trajectory planning, supporting facilities and commercial designs. Finally, we discuss the challenges which might be faced while developing and commercializing FCTS from three aspects: safety issues, commercial issues, and ethical issues.

Flying Car Transportation System: Advances, Techniques, and Challenges

In order to fulfill transportation demands, people have well-explored ground, waterborne, and high-altitude spaces (HAS) for transportation purposes, as well as the underground space under cities (namely, subway systems). However, due to the increased burdens of population and urbanization in recent decades, huge pressures on public transportation and freight traffic are introduced to cities, plaguing the governors and constraining the development of economics. By observing the fact that near-ground space (NGS) has rarely been utilized, researchers and practitioners started to re-examine, propose and develop flying cars, which are not a totally novel idea, aiming at solving the traffic congestion problem and releasing the strains of cities. Flying cars completely differ from traditional grounded transportation systems, where automobiles/trains are suffering track limitations and are also different from the air flights in HAS for long-distance transfer. Therefore, while observing the lack of specific literature on flying cars and flying car transportation systems (FCTS), this paper is motivated to study the advances, techniques, and challenges of FCTS imposed by the inherent nature of NGS transportation and to devise useful proposals for facilitating the construction and commercialization of FCTS, as well as to facilitate the readers understanding of the incoming FCTS. We first introduce the increased requirements for transportation and address the advantages of flying cars. Next, a brief overview of the developing history of flying cars is presented in view of both timeline and technique categories. Then, we discuss and compare the state of the art in the design of flying cars, including take-off \& landing (TOL) modes, pilot modes, operation modes, and power types, which are respectively related to the adaptability, flexibility & comfort, stability & complexity, environmental friendliness of flying cars. Additionally, since large-scale operations of flying cars can improve the aforementioned transportation problem, we also introduce the designs of FCTS, including path and trajectory planning, supporting facilities and commercial designs. Finally, we discuss the challenges which might be faced while developing and commercializing FCTS from three aspects: safety issues, commercial issues, and ethical issues.

Car use reduction: a matter of reasoned calculus, morality or habit? An integrative perspective

Car transportation has many benefits, yet it also generates problems such as noise and air pollution, loss of urban space, traffic jams and contributes significantly to global warming. Three approaches for explaining car use behavior and intentions to reduce it are often used in the transportation literature, namely a rational choice (e.g. theory of planned behavior), a morality-based (e.g. norm activation model) and a habit-based approach. While there were studies that investigated their comparative power, there were relatively few attempts to integrate these different perspectives in a single theoretical model. The present study proposes an integrated model of the theory of planned behavior, the norm activation model and the concept of habits to predict drivers’ intentions to reduce their car use, and tests this model on a sample of Romanian drivers (N = 140). Results show that the model performed better than the theory of planned behavior, the norm activation model or a combination of the two and that all variables in the model predicted (directly or indirectly) behavioral intentions to reduce car transportation. The strongest predictors were perceived behavioral control, personal norms and car use related habits. The results contribute to theory development and provide a conceptual framework, which can inform the development of future travel demand management solutions.