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In India, priority rules at un-signalized intersections are often ignored by drivers. The present paper reports the applicability of deterministic and probabilistic methods for estimating the critical gaps at high-speed un-signalized T-intersections. The critical gap is estimated for different vehicle types and crossing movements. The study quantifies the implication of critical gap values on the capacity and safety values at un-signalized T-intersections. The results point to conclusion that the value obtained for the critical gap using deterministic methods is lower than that estimated by the probabilistic method. The gap values estimated using the Binary Logit Regression method are similar to those computed using the equation reported in Indo-HCM (2017). It was concluded that a lower value of the critical gap yields a higher capacity value and a higher value of risk probability.

This paper discusses the issue related to the switching regulators operated at high switching frequencies, where it is necessary to eliminate the influence of parasitic components of the converter's main circuit. In more detail it deals with the node-ringing phenomena, which is typical for synchronous buck converters. The existence of the parasitic inductances arising from the printed circuit board conductive paths, induce voltages, which are several times higher than nominal input voltage, thus it increases the risk of damage of the power transistors. Therefore, optimization of the circuit is required to reduce the voltage spikes and therefore improve safety margin related to nominal operation. In this paper, node-ringing phenomena is introduced, while the optimization methodologies for its reduction are described and verified by experimental analysis.

The paper deals with the brushless torque motor, that was designed for precise positioning device to substitute servo drive for high torque and low speed application. It describes the design, basic parameters as well as the analysis of torque characteristic. The paper also presents the results of realized measurements. Finally, the parameters of the brushless torque motor and servo drive applicated in precise positioning device are compared. A series of measurements like measurement of torque characteristics, loading characteristics and also measurements of drive performances are presented in this paper.

Intelligent transportation systems (ITS) are a today´s hot topic, especially in the context of the development of information technologies, which can be employed in transportation. Although the scope and the technical solution of these systems may vary, they are frequently based on VANET (Vehicular ad hoc network), i.e. a communication network, which is primarily generated among the moving subjects, which form ITS. Given the highly dynamic VANET, the questions are raised as to the data transmission. This paper is aimed to make a detail analysis of the communications within VANET using the simulation model, which includes the static infrastructure of ITS and to experimentally verify the impact of this infrastructure on the dynamics of information spreading in ITS. The authors present the results obtained from a few different scenarios, which have been tested.

Changes in road construction are affected by the owner and contractor at the beginning, middle, or end of the project. This study aims to determine the ranking of the factors that cause change orders for road construction from the owner's point of view. Data was collected by distributing questionnaires and interviews to project owners. Reliability and validity tests involving 32 respondents resulted in 48 causes of change orders. This study quantifies the relative importance of the factors that cause change orders and shows the ranking of factors and groups that cause change orders according to their level of importance for causes of change orders. This goal is achieved through the analysis of the results of the interviews. According to the calculation of the Relative Importance Index (RII), all the factors and groups are ranked and the most significant ranking is determined regarding the causes of the change orders.

The design of a bicycle frame in Creo Parametric and the following simulation comparison of three frame materials - steel, aluminium and carbon, using the software from Marc Mentat, are the main subjects of this article. In this article, the authors explain how to model a bicycle frame in three dimensions and contrast it with frames made of the other two materials. The simulation's findings demonstrate how various elements, such as load, affect a steel, aluminium and carbon frame's behaviour in specific circumstances and under identical settings. Engineers may choose the best material and optimize the geometry and topology of the frame, based on the findings of the simulation, to get the best outcomes in terms of the stiffness requirements and rider comfort.

Angular ball bearings are commonly used whenever there is a demand to increase stiffness of a bearing. The aforementioned increase of stiffness can be achieved by obtaining proper preload in bearings. In common belief, preload has a negative consequence: it increases the load of rolling elements, which must lead to lower durability of bearing compared to the situation before the preload use.

Cities are often characterised by the presence of universities and by a greater number of students, often commuters, with an average age of less than 30 years. The study focused on the city of Enna (Italy), where the university students represent a significant percentage of residents and also a good rate of local travel demand. The survey campaign was conducted over a period of more than one year. A bivariate statistical method was applied highlighting significant variables regarding several features of a car sharing system. Additionally, non-parametric statistics and a before and after analysis were performed to evaluate the influence of implementation of the shared transport service. The results can also offer insights into the improvement of transport supply in urban context and the possible implementation of the co-creation actions between the companies managing the service with the end-users.

The highways that are used in the countries with a sharp continental and a hot climate operate in the conditions when the pavement temperature changes along its height. This fact can lead to a significant increase in stresses in the layers of the road structure. In this paper is suggested an approach to solution of the joint problem of the pavement deformation and the heat propagation in it by a finite element modelling technique. The ANSYS software package was applied to solve the described problem. It is shown that an increase in the road surface temperature leads to a significant increase in the von Mises-equivalent stresses in the asphalt concrete upper layer and that is the cause for the ruts formation. Computational results also showed that at low temperatures of the road surface, the significant tensile stresses arise in its upper layers and that leads to formation of cracks.

The article describes an advanced test stand for measuring temperatures during the 3D printing for additive manufacturing. Based on mathematical procedures, it analyzes the impact energy of the laser beam used in metal 3D printing.

This article presents an analysis of the supply and demand of a FFBSS recently implemented in the city of Bologna, Italy. The main aspects treated in this paper are: analysis of bike availability; temporal analysis of FFBSS demand; calibration and validation of a novel model that predicts the number of daily trips per available bike. This model is based on a linear combination of several day attributes, including meteorological and day-type attributes. Moreover, an origin to destination analysis is generated showing the spatial distribution of FFBSS trips. The methods are applied to a scenario with almost a million GPS traces recorded between July and October 2018 by the FFBSS in Bologna. Findings could support FFBSS companies to better understand the fluctuation of both the transport demand and supply of this relatively recent transport mode, as to make more efficient decisions when distributing or relocating bicycles.

The paper presents an analysis and comparison of selected dynamic parameters in the common crossing and switch unit of a railway turnout. The paper includes a description of the measurement methodology, the report of mathematical methods used to evaluate the measured data and comparison of selected parameters describing dynamic processes in individual parts of the structure. The paper also includes a mathematical analysis of the lesser-known Hilbert Huang transformation, including its practical application. From the presented case study, practical experience and recommendations for the railway line managers, research organizations and possibly for the wider technical public are derived.

The article deals with method of purifying the exhaust gases in an automobile muffler or other transport equipment using electrical pulses. Electrical pulses are formed between the two ring electrodes (anode and cathode) installed in series along the gas flow. The physical picture of the process is described. A mathematical model has been developed and studied. A deterministic relationship has been established between the engine volume, the number of the crankshaft revolutions, the electric field strength and the charge strength and dynamic viscosity of the gas. Experimental studies have been carried out. The goal of the experiment was to confirm the hypothesis of impact ionization of exhaust gases. The effectiveness of electrical pulse purification has been proven.

Earthquake and tsunami preparedness is important to plan, especially in the earthquake and tsunami-prone areas, such as Banda Aceh. This study evaluates the tsunami evacuation routes' performance using the width of the road, travel time and the Degree of Saturation (DS) parameter. Some of the Degree of Saturation (DS) of the road segment surprisingly reach 1.0 to 3.18, exceeding the recommended 0.75 standard DS ratio. That indicates that the existing roads cannot accommodate traffic flow during evacuation. This study recommends the evacuation process by walking. Thus, developing the pedestrian routes according to evacuation safety requirements is strongly encouraged. Further, more escape buildings reachable within 15 minutes of evacuation time should be planned in the area. The pedestrian routes need to be designed separately from that of the traffic flow.

The article presents selected results and the sequencing of research into the project "Long-Term Monitoring of Rail Structures in Tramway Crossings with a Focus on Shallow-Grooved Crossings Aimed at the Optimization of their Maintenance and Noise Reduction", which was running with support from the Technology Agency of the Czech Republic within the Zeta Project (project registration No. TJ04000257) in 2020-2022. The project was elaborated jointly with the Prazska strojirna a.s. Company in cooperation with the Prague Public Transit Company (hereinafter PPTC). The project's objective was to optimize the maintenance of tramway tracks with a focus on shallow-grooved crossings in rail structures taking into account the noise emission levels during the life cycle of these crossings.

Computational models of artificial neural networks are currently used in different areas. Accuracy of results exceeds the performance of traditional statistical techniques. Artificial neural networks as the Kohonen map may be used e.g. to identify industry leaders, thus replacing the traditional cluster analysis and other methods. The aim of this contribution is to analyse the transportation industry in the Czech Republic by the Kohonen networks and identify industry leaders. The data file contains results - division of companies into a total of 100 clusters. Each cluster is subjected to analysis of absolute indicators and several parameters, average, as well as absolute, are examined. In total, 88 firms may be considered as industry leaders. Consequently, a fairly small group of companies has a strong influence on development of the whole transportation industry in the Czech Republic.

The big modern ships are the largest mobile objects that exist in nowadays world. Their huge mass and length in combination with their limited maneuverability can result in the risk of extreme destructions of the infrastructure, as well as environment, in the case of even minor malfunction of any of its elements. The main danger is the kinetic energy of such a colossus and in these circumstances the accuracy of information on the ship's speed becomes particularly important. This is the reason of a growing interest in various systems designed to support harbor pilots during the maneuvers. The most popular ones are based on laser-measurement of the distance, as the rule, installed as static installation in the quay.

In principle, every vehicle is equipped by a suspension system, which usually consists of springs and shock absorbers. The main purpose of the suspension system is to eliminate vibration of sprung and unsprung masses. Therefore, the proper operation conditions of the shock absorbers affect in a fundamental way total running properties of vehicles. However, during operation, shock absorbers are being worn out or they can even be damaged. Then, such a situation is unwanted and it has to be detected as soon as possible. The content of this article is focused on analysis of vehicles' shock absorbers defects. Methods for detection of possible shock absorbers faults are presented. Further, a proposal of the method for detection of a state of a hydraulic shock absorber during its operation is presented. The method uses identification of the temperature change of a hydraulic shock absorber during operation.

The article presents the results of the strength analysis of the chain binder components for symmetry fixing a wagon on the railway ferry deck, taking into account the actual hydrometeorological conditions of the navigation area. The simulation of the wagon dynamic load during the railway ferry rolling was carried out to determine the loads acting on the chain binder. The strength of the chain binder hook was analysed. The calculation results showed that the maximum equivalent stresses in the hook occur in the radial part and exceed the allowable ones by 23%. Therefore, to ensure the strength of the chain binder, it is necessary to comply with the appropriate roll angles of the railway ferry or create measures to reduce its load when rolling. The conducted studies will contribute to ensuring the safety of wagon transportation by sea and increasing the efficiency of rail-ferry transportation.

This article deals the implementation of a SiC MOSFETs in a three-phase inverter module, intended for use in auxiliary converters for powering electrical appliances of railway wagons. The basic properties of the SiC semiconductor elements and their differences, compared to IGBT modules, are summarized here. The given block diagram describes the individual blocks of the inverter module and their interconnection. Finally, a measuring setup for measuring the efficiency of inverters is presented. The measured efficiency values of the proposed SiC inverter and the original solution with IGBT modules are compared in the given graphs.

Estimation of the optimal size of order is one of the key tasks in determining the parameters of the urban freight restocking system. The existing analytical models and methods are considering each technology separately and they do not compare the Economic Order Quantity (EOQ) and Just-in-tme (JIT) restocking technologies. The purpose of this research was to evaluate efficiency of the JIT and EOQ restocking technologies. The research would help in selecting the delivery model, analyzing functioning of existing JIT and EOQ models. The article presents an approach to determining the comparison in organizing supplies to the retailer. For this, the two supply models were compared. The Just-in-Time model is characterised by costs that are spend on transportation. The Economic Order Quantity model includes costs of transportation and storage in a warehouse. After calculations, application of the Just-in-Time model in the given conditions was determined.

Speeding or driving above the speed limit might be conducted due to various reasons. This paper is intended to investigate whether there are certain underlying behaviors that trigger speeding in the various driving environment. Authors were investigating the effect of boredom proneness, impulsiveness and sensation seeking on driver speeding behaviors. They received 676 responses to our distributed online questionnaires mainly from Lampung, East Java, East Borneo, North Celebes and North Moluccas. A Structural Equation Modelling (SEM) was conducted for analysis. The result implies that the drivers with high sensation seeking, low boredom proneness and high impulsiveness tend to drive at high speed.

The 33.0 m long reinforced concrete bridge beams of the overpass superstructure after vehicular impacts were taken as a research object.
The overpass consists of 14 beams, six of which were repaired by restoring the widened lower part with EMACO FAST TIXO, manufactured by BASF.
The remaining 8 beams were completely dismantled and replaced with new ones. The new beams have been fully tested for the perception of vehicular loads. The fully reconstructed span structure showed compliance with the design loads of A14, NK-120 and NK-180 based on test results.

The main objective of our research was to map the exposure to electromagnetic smog in the frequented space of shopping centres in the city of Bratislava and to compare our results to the actual hygienic limits. The measurements of the low- and high-frequency electromagnetic fields were performed at different places in shopping centres. Our results did not exceed the Slovak current limits in any of the measurements. However, almost all of them markedly exceed new permitted limits according to EUROPAEM. Based on our results, stricter limits in many European countries and increasing evidence on possible harmfulness of long-term exposures to artificial electromagnetic fields, preventive carefulness can be recommended - to support the research in this field, to prepare professional public education and possibly to prepare the stricter Slovak exposure limits.

The aim of this research was to find out the specific geometrical parameters of the harmonic drive with the greatest impact on its lost motion. Harmonic drive units are widely used in production automation, robotics and automated manufacturing systems. Virtual model of Harmonic Drive was examined using the finite element method. The analyses were performed with considering the real test conditions of high precision gearboxes with a lost motion value of 4 % of the nominal output torque. The analyses' results were then used to develop a unique approach to obtain a functional relationship between the input parameters defining the shape of the flexspline and the harmonic drive lost motion value. Subsequently, the global sensitivity analysis was performed to determine the degree of influence of the selected flexspline parameters on the harmonic drive kinematic accuracy.

A promising type of cargo vehicles are mobile ropeways formed by autonomous self-propelled rope units connected by a common cable transport system. The article presents a method for predicting the kinetics of the reliability indicators of the ropeway as a whole, individual rope units and their subsystems, taking into account the timing and volume of planned repairs. This method is advisable to use at the design stage of rope units, as it allows one to simulate the stage of their operation and provide the required level of reliability based on proactive replacement of structural elements that have reached the maximum permissible probability of critical failure. The method makes it possible to solve a number of important technical and economic problems related to operation of units and ropeways, including the development of an optimal strategy for their planned repairs, which has a minimum cost.

Due to the large amount of available data in this study, authors have utilized data mining algorithms, especially the decision tree, to process these data and obtain the information, which would result in increasing road safety, determining the causes affecting it and patterns leading to traffic accidents. The effective use of this tool and its role in controlling the number of driving accidents is the subject of this study with the help of data mining algorithms. The results show that the increase in the number of roadside assistances to more than 41; number of driving accidents (fatally injured) is not significantly different, hence one of the proposed strategies for intelligent relay stations and its organization with the intelligent transportation tool is available. The intelligent transportation system utilities comprise of monitoring, guidance and enforcement tools, plus service tools such as rescue, driver assistant and road improvement.

The article shows a fragment of the results of the author's concept of road safety management in Poland. The article shows the "program sequence" of the construction action of road safety management system in Poland. The main component of this "sequence" of actions to improve the road safety - should be the "road risk management model". It should be widely used in Poland as an element of knowledge and practices of international road safety management. It is primarily about the model of the Office for Land Transport Safety Authority in New Zealand adopted by the EU in its road safety policy. The article also presents other components of the author's concept, including the "3 levels" model of risk management, the idea of which is to isolate three categories of the risk associated with any transport system.

Present study evaluates the various congestion indexes in terms of speed performance index, volume to capacity ratio and congestion index based on travel time on the urban roadway network of 5.7 km in length, operating with mixed traffic conditions (traffic with varying static and dynamic characteristics of vehicles). The mitigations measures have been proposed to cater to the present traffic demand by converting the uncontrolled intersection to a partially controlled or signal-controlled intersection. In order to check the effectiveness of such mitigation measures, various scenarios have been generated in the developed and a well calibrated simulation model. It has also been observed that the speed performance index has improved by 8.88 percent while providing channelized intersection at one of the point elements and 11.52 %when the two-point elements have converted to channelizing intersection.

The article deals with the existing methods of cleaning vehicle radiators from sedimentary scale. A method of cleaning radiator tubes by ultrasonic radiation is proposed. An experimental bench has been developed for studying ultrasonic cleaning processes. Based on the results of the experiment, dependences have been obtained that determine the efficiency of the process depending on the mass of scale removed and the liquid outflow rate from the tubes. There are proposed the purification degree coefficients. The hypothesis about the possibility of cleaning radiators with ultrasonic vibrations has been confirmed.