The vehicle exploitation system, consisting of statistically identical objects that perform intervention tasks, not subject to systematic changes, can be modelled as a stationary stochastic process. Such a model allows to determine the probabilistic indicators of current and boundary readiness of the system. This article presents the use of the semi-Markov process, based on three operating states: operation, ready-to-be-used and repair, to study a transport system consisting of special vehicles. On the example of a sample consisting of police patrol cars, experimental studies of the intensity of fleet utilization, time of failure-free operation of vehicles were carried out, and it was demonstrated that the examined transport system is characterized by a satisfactory, stationary readiness coefficient. The developmental possibilities of the presented modelling method were emphasized.

The aim of the article is to compare the operational efficiency of the city buses in various stages of their operational life. Technical readiness tests, repair costs and revenues during the six years of operation were conducted using two popular bus makes as an example (domestic and imported). Based on these tests, the characteristics of the operational efficiency of buses was determined. It has been shown that the service life has a significant effect on the operational efficiency. The division of the total operational period of the vehicle into the warranty and post-warranty period was considered and a new division was introduced, of the „period of full operational usefulness” and “period of limited operational usefulness”. This new division of service life into stages makes it possible to determine the most reasonable limit of the vehicle usage until it is taken out of service. It can also be used when choosing a vehicle make as part of a fleet renewal or extension program.

A driving cycle is a time series of a vehicle’s speed, reflecting its movement in real road conditions. In addition to certification and comparative research, driving cycles are used in the virtual design of drive systems and embedded control algorithms, traffic management and intelligent road transport (traffic engineering). This study aimed to develop an adaptive driving cycle for a known route to optimize the energy consumption of an electric vehicle and improve the driving range. A novel distance-based adaptive driving cycle method was developed. The proposed algorithm uses the segmentation and iterative synthesis procedures of Markov chains. Energy consumption during driving is monitored on an ongoing basis using Gaussian process regression, and speed and acceleration are corrected adaptively to maintain the planned energy consumption. This paper presents the results of studies of simulated driving cycles and the performance of the algorithm when applied to the real recorded driving cycles of an electric vehicle.

The aim of this study was to analyze the impact of the categories of bus downtime caused by the necessity of their repair on the availability indicator. A retrospective study covering 12 years of bus operation was carried using the selected municipal transport company as an example. The share of the selected categories of downtime in the total time of vehicle downtime was analyzed. The Spearman’s rank correlation coefficient was used for the analysis. The research covered seven makes and types of buses and six categories of downtime. A ranking of the downtime categories was developed according to the criterion of the statistical dispersion of stoppage time as a measure of their unpredictability. It was shown that categorized unavailability was strongly dependent on the rank of downtime and loosely dependent on the age of buses. In practical applications, the test results may be useful in improving the fleet maintenance processes, selecting the make of new buses or development of models for safety margin availability.

Contemporary research on electric buses focuses mainly on the following issues: energy efficiency, range and transport costs, and traction battery technology. However, little research has been conducted on operational reliability. This article presents a comparative assessment of the reliability of electric buses in relation to combustion engine buses. The research was conducted under real conditions in the city of Lublin, Poland. The reliability functions of buses and their structural components were determined based on the Weibull distribution. It was shown that electric buses have a shorter distance between failures than combustion engine buses of analogous capacity. The statistical significance of the differences in reliability between electric and combustion engine buses was verified. The suitability of the Weibull model as a model of bus reliability in comparative studies was verified. The results of the research can be used to monitor current sustainable public transport development programs and to improve bus diagnostic and maintenance systems in transport companies.