No abstract

Taking into account the importance of time spent on passing distances of vehicle routes that lie across city road network (RN), well-known approaches to the determination of vehicle delay in the movement process (waiting for passage and the passage) of controlled intersections are analyzed. Reasons that cause the growth of these delays and that have an impact on traffic light cycle duration are counted. At the same time, the authors justify the need for change in the existing term transport delay. It should be interpreted (concerning intersection passage) as a delay only in the case when the group of vehicles that have stopped before intersection could not pass this intersection during the permission signal and wait for the next such signal. If the vehicles in the first group could pass the intersection (possibly taking into account also waiting for the permission signal), then this is not a delay but the necessary component of the technological process of the route passage. From this point of view, an approach in the traffic delay determination method at controlled intersections is proposed taking into account the particular components of Webster`s formula and the volume-capacity ratio of RN that determine the motorization level of the city population. A comparison of the results of delay calculation, determined with the use of the proposed method and Webster's formula, is carried out.

The object of this study is the process of determining the dynamic indicators of the pneumatic spring, which is used as the main element of the second stage of spring suspension in the high-speed rolling stock of the railroad, based on the influence of the geometric parameters of the connecting pipeline. It has been established that the dynamic indicators of rolling stock mainly depend on the operation of the pneumatic spring, the characteristics of which are largely determined by the geometric parameters of the connecting element between the pneumatic spring and the additional tank. A mathematical model of oscillations of a dual-mass system has been constructed, the elements of which are connected through a pneumatic spring suspension system. The operation of the pneumatic system is described using the Boyle–Mariotte equations, the state of the ideal gas, the energy for the flow in the connecting pipeline, and the law of conservation of energy. Theoretical studies into the influence of the diameter and length of the connecting element of the pneumatic spring suspension system on energy loss and damping coefficient for the cycle of its operation and the rigidity of the pneumatic spring have been carried out. It was established that the dependence of the stiffness of the pneumatic spring, while changing the value of the diameter of the connecting element from 6 mm to 30 mm, is nonlinear. In the process of compression, the rigidity of the pneumatic spring changes with the length of the connecting element of 1 m from 927 kN/m, static rigidity, to 497 kN/m, dynamic rigidity. The dependences of energy loss and damping coefficient for the operation cycle of the pneumatic spring suspension system based on the hysteresis loop have been constructed. It was found that the difference between the damping coefficient in the process of compression and expansion of the pneumatic spring is no more than 4 %. It was established that the design of high-speed rolling stock is impossible without high-quality modeling of the process of operation of the pneumatic spring suspension system

Intelligent Transport Systems in urban conditions is one of the solutions to reduce congestion of vehicles and the amount of harmful emissions. An important component of ITS is the assessment of the duration of a public transport trip. It is necessary to focus on the study of the duration of the bus (the duration of traffic between stops and the dwelling time). In this paper, the authors focused on determining the dependence of the duration of buses at stops depending on the demand of passengers. The dwelling time of buses at stops is not considered independent of the duration of the journey. The duration of the bus is the periods of time when the buses wait at the stops, and the travel time, which is the duration of the bus between each two stops. The study was conducted on the bus route #3A in Lviv. To determine the dwelling time of the bus at stops, it is necessary to take into account information about passengers and the trajectory of buses. The obtained data can increase the accuracy of forecasting in different traffic situations in comparison with the most modern methods.