Railway infrastructure must meet safety requirements concerning its construction and operation. Track geometry monitoring is one of the most important activities in maintaining the steady technical conditions of rail infrastructure. Commonly, it is performed using complex measurement equipment installed on track-recording coaches. Existing low-cost inertial sensor-based measurement systems provide reliable measurements of track geometry in vertical directions. However, solutions are needed for track geometry parameter measurement in the lateral direction. In this research, the authors developed a visual measurement system for track gauge evaluation. It involves the detection of measurement points and the visual measurement of the distance between them. The accuracy of the visual measurement system was evaluated in the laboratory and showed promising results. The initial field test was performed in the Vilnius railway station yard, driving at low velocity on the straight track section. The results show that the image point selection method developed for selecting the wheel and rail points to measure distance is stable enough for TG measurement. Recommendations for the further improvement of the developed system are presented.

The article discusses the problem of railway safety management and the criteria for evaluating the traffic risk described in various scientific publications. The research aims to assess the risk posed to railway infrastructure objects and to create a model for safety risk evaluation. The research on the traffic safety risk with respect to the infrastructure of the rail transport system was divided into three stages. The Plan–Do–Check–Act (PDCA) model can be used for investigating the problem of managing railway traffic safety risks in the Lithuanian railways. The main threats to railway infrastructure objects are defined, and the catalogue of technical parameters of level crossings of the Lithuanian railways is presented. The maximum allowable train speed, the intensity of railway and road traffic, as well as the size (width) and visibility of level crossings from the train driver’s cab are chosen as the main criteria for evaluating the vulnerability of a level crossing. The logistic regression method has been applied to rank and assess the safety of level crossings of the Lithuanian railways. The validity of the model developed in the present work for assessing traffic safety risks at level crossings of Lithuanian railways is about 86%. The suggested risk evaluation model is flexible and can be easily adapted for the evaluation and monitoring of safety risk of other elements pertaining to railway infrastructure. Finally, the basic conclusions and recommendations are provided.

An improved method for spectral analysis of traction current of an Alternating Current (AC) electric locomotive is considered in the article. A new method of spectral analysis considers the change in voltage in the catenary system as a non-deterministic, non-ergodic and non-Gaussian process. It has been established that higher voltage harmonics in the catenary system have a significant negative effect on the operation of non-traction railway consumers of electricity. In addition, electric locomotives operating in the same feeder zone have a mutual influence on each other. Electric railway transport is a source of higher voltage harmonics and strongly distorts the shape of the sinusoidal voltage of the catenary system, which are caused by the higher spectral components of the current in the electric locomotive traction drive circuit. These spectral components of the traction current arise in the traction drive circuit due to the nonlinearity of the current-voltage characteristics of the electronic devices of an electric locomotive, for example, a contact rectifier, a capacitor circuit of traction motors. Reactive power compensators are used in electric locomotives to eliminate components of higher harmonic traction current in the catenary system. Traditionally, spectral analysis in such systems is performed using Fourier methods. However, the determination of the spectral components of the traction current by the Fourier method for constructing a control system for a reactive power compensator is possible only if the process of voltage variation is a deterministic or ergodic Gaussian process. Otherwise, the application of Fourier transform methods will be incorrect. An analysis of the factors that affect voltage changes in the catenary system showed that this process is significantly different from the ergodic Gaussian process. Such factors include the following: the operating mode of the electric locomotives; number and total capacity of electric locomotives in one feeder zone; electric locomotives passing through feeder zones; instability of collection current. Thus, in the case under consideration, the application of the Fourier methods is incorrect for the analysis of the spectral components of the traction current. This affects the quality of compensation of the higher harmonic components of the traction current, and in some cases, the unstable operation of the control system of the active part of the reactive power compensator. Proposed scientific approach is based on the Levinson–Durbin linear prediction algorithm. On the one hand, this allows adapting the control system of the compensator to the voltage parameters of the catenary system. On the other hand, this allows taking into account the operating modes of electric rail vehicle with reactive power compensation. The construction of a compensator control system using the Levinson–Durbin algorithm significantly simplifies thensynchronization scheme of the compensator and power circuits of the traction electric drive of AC electric locomotive. A comparison of the traditional method of spectral analysis, based on the Fast Fourier Transform (FFT), and the method, based on the Levinson–Durbin algorithm, proposed by the authors, showed the high efficiency of the latter.

The article describes the assessment of safety of Lithuanian Railways level crossing. The statistical analysis of the railway accidents in Lithuania and abroad in recent years has shown that about 30% of all transport accidents in railway occur at railway level crossings. The safety assessment of the country's crossings is carried out considering the following technical criteria: the category of crossing, visibility, the intensity of the movement of trains and road vehicle, the width of the railway crossing, and the maximum speed of trains. Applying the binary model of logistic regression, the probability of accidents at the 337 railway crossings of the country was calculated. Depending on the degree of risk or the probability of accident, the country's railway crossings are ranked. The most dangerous crossings of four regions in the country were identified. Finally, the main conclusions and recommendations are presented.

In today’s world, with the acceleration of technological processes and the emergence of the wave of the COVID-19 pandemic, all production and service sectors, especially transport companies, are experiencing new challenges of technological development. The technological development of a transport company and the efficiency of road transport logistics depends on all the resources used and the latest implemented technologies. The authors analyse and evaluate the synergy of technological development and logistic cooperation. A synergy connection model is created to assess the interaction between logistic cooperation and technological development, and this synergy impacts the transport company’s activity. Three groups of factors are arranged for the defining of the level of synergy of logistics cooperation and technological development of road transport companies: the first, the influence of technological development on the effective use of IT; the second, the influence of technological development on the quality of innovative equipment; and third, the impact of technological development on the level of staff competence. The Alternative Hierarchy Processing (AHP) method was chosen to assess these factors’ importance as AHP enables quantifying the evaluation, i.e., gives numerical values for quality criteria. The synergy of transport company technological development and logistics cooperation is ensured mostly by the compatibility of transport system technologies and the technological literacy of logistic employees. It has been established that this factor is decisive for the formation of road transport companies’ technological development and logistic cooperation processes. Finally, the conclusions and recommendations are given.