Influence of mountain traffic conditions on the functional state of a bus driver

Ensuring the transport process requires proper interaction of all parts of the system "driver - car - road - environment" and its subsystems. In this case, the driver is often a "weak" component of the system, and his actions can reduce the level of road users` safety. It should be noted that the reliability of the driver can be considered as the probability of his trouble-free and error-free operation, as well as the proper level of his regulatory mechanisms functioning. In this case, to analyze the activities and readiness of the driver for his professional activities, indicators of functional status are often used. Thus, the study of the "human factor" in the transport process is an important task to ensure the reliability of the whole transport system. Today the most of all transportation is carried out by road. The timeliness and safety of cargo delivery and passenger safety depend on the driver's actions. At the same time, the driver is influenced by a considerable number of external environmental factors during his work. One of the most important factors is the mountainous traffic conditions, which often have many changes in plan and the profile of roads. Another feature of such traffic conditions is the height above sea level, affecting the human body, particularly its functional state. Considering the above, the paper measures the heart rate variability of bus drivers moving on a route that was partly in the mountain's conditions. During the research, video recording and registration of the vehicle's geolocation were also carried out. This made it possible to establish indicators of the driver`s functional state in specific periods. After processing the obtained values, the influence of mountainous traffic conditions on the bus drivers` indicator of regulatory systems’ activity was established.

Minimization of traffic delay in traffic flows with coordinated control

The method and results of transport research, carried out by field research method, on the determination of the main indicators of traffic flows with significant unevenness of the movement on the arterial street in conditions of coordinated control is reviewed in the paper. Time parameters of traffic light control for which a reduction in traffic delay is achieved in direct and opposite traffic flow by the change of permissive signal depending on traffic intensity are determined using the simulation method. Change (increase) of the duration of the permissive signal provides uninterrupted movement of vehicles` group during their passage of stop-line at traffic light objects. The proposed method can be used on sections of transport networks with coordinated control, where there is significant heterogeneity of traffic flow, and it prevents the dissipation of groups that consist of vehicles with different dynamic characteristics. Such a result is being performed in the case when in the system of automated control, which combines adjacent intersections on an arterial street, fixed-time program control of traffic light signalization is operating. In this condition, there is a possibility to adjust the duration of signals of traffic light groups by correcting the width (permissive signal duration) and angle of inclination (speed of movement) of the timeline in coordination graphs. The scientific novelty of this research is that the method of traffic delay minimization in conditions of coordinated control acquired further development. The essence of the method is in the controlled change of the range of permissive signal duration in conditions of simultaneous control of the speed of movement between adjacent intersections. Practical value is the application of different programs of traffic light control on sections of arterial streets in transport districts where a significant difference of values of traffic intensity by directions is in morning and evening peak periods.

Formation of traffic safety profile in central parts of the city and its informational protection

Nowadays, there is a difference between European and domestic approaches to the functioning and organization of road networks, urban mobility, and effective use of the space of urbanized territories. The main factors were historical development, scientific-technical progress, an administrative component in the formation of financial flows to developing urban systems, terrain, the process of territories` urbanization, and the formation of urban agglomerations. These factors had a direct impact on the shape of the modern state of the road network. The process of Intelligent transport systems integration into the system of domestic cities requires complex approaches, in particular, consideration of the parametric structure of elements, application of communicators not only for the control of traffic flows from the outside but also from the inside, which will allow speeding up the information change in the system. One of the elements of the combination of morphologic elements of the urban environment is the practical application of the criterion of street and road infrastructure interaction and the concept of traffic safety profile. This is a result of a combination of all morphological features and variants of their configuration. In current conditions, a new approach in research is necessary to determine criteria and factors of sustainable development of transport systems. This approach allows operatively considering the changes of the external environment, reacting adequately to the changing behaviour of competitors providing services and consumers, and effectively impacting the demand and supply of transport services. A concept of effectiveness is required to consider both the transport system in general and its separate elements. Implementation of progressive methods of system control of transport flows provides, in conditions of rapid motorization and increasing the urbanized territories areas, obtaining the most significant effect in short terms and allows maximal using the possibilities of urban transport networks.

Assessment of the noise level on arterial streets depending on traffic flow indicators

The intensity of traffic flows increases every year and intensifies its impact significantly on urban territory's ecologic situation and natural environment. In Ukrainian cities, the growth of noise pollution is quite a topical problem as it has a significant impact on the environment because of the increase in car numbers. Traffic flow intensity and densification of the built-up area cause the increase of the noise level. As analytical methods of calculation of determination of traffic noise level have several disadvantages, then for assessing the level of noise on arterial streets of Lviv city, research is carried out with consideration of traffic flow indicators. One of the critical criteria that have an impact on noise pollution in the urban environment is traffic flow composition. Conducted research indicates that the speed of traffic flow creates significant noise pollution, especially on those streets where cobblestone is a road pavement. Freight and passenger transport that moves along arterial streets causes the increase of noise level and increases its impact on the city territory. On sections of arterial streets in peak periods of the day with high values of volume-capacity ratio and general share of freight and public transport of more than 30% in a flow, the noise exceeds the acceptable norms and has a harmful impact on the environment. That is why it is necessary to assess noise pollution and the development of protection measures from noise during the planning and construction of some urban regions or residential areas. It is established that to lower the noise level on streets, it is necessary to consider existing intersections of arterial streets and the regime of movement on them. To lower transport noise, it is necessary to distribute freight and transit transport by city streets more rationally, use qualitative public transport, and limit the maximal speed regime on city streets. Further research on the road network will provide an opportunity to assess the noise level distribution of traffic flows in Lviv city. It will help to determine the problem places and propose methods of combating traffic noise.

Assessment of sustainability of the Lviv city transport system according to the indicator of accessibility

Transport accessibility of the territory determines the possibility of getting a certain area using a certain transport mode of the existing transport network. The paper describes the concept of accessibility of the territory as a factor of sustainability of the urban transport system and methods of its assessment for urban conditions. It is proposed to use the indicator of the number of non-stop public transport routes between transport zones as a criterion for the "cost" of travel. Non-stop travel increases the comfort of public transport and reduces the financial costs of the passenger. The route network of the city of Lviv and interconnections of transport zones by public transport routes (bus, tram, and trolleybus) are analyzed. Modelling of passenger traffic volumes and their distribution by modes (private transport, public transport, and pedestrian traffic) was done in the PTV Visum software based on the matrix of a duration of movement and the matrix of the number of non-stop routes. It was found that at commensurate distances between transport zones, the number of non-stop routes increases the share of public transport users. The relationship between the number of non-stop routes and the share of public transport users is described by the logarithmic dependence. Comparing the simulated passenger flows on the public transport routes with the results of field researches, it was found that taking into account the number of non-stop routes between transport zones during the simulation allows increasing the accuracy of the results. Further research may focus on analyzing the impact of other factors that characterize the accessibility of the territory on the distribution of transport users between modes, and on the development of recommendations to the responsible city authorities to improve the city's passenger route network.

Assessment of the external mobility to Ukrainian cities

The problem of citizens' mobility is crucial for most Ukrainian cities. At the same time, besides urban travelling, external travelling also impacts the urban transport system. That is why the study of regularities of external mobility will allow considering it during urban systems planning. In this article, the movement of citizens to Ukrainian cities with a population above 70 thousand persons is reviewed. The source of the data is information from mobile operator Kyivstar. The connection between the quality of life in cities and the general level of external mobility (depending on the number of citizens in cities, they are divided into five clusters) is established. It is detected that larger mobility is inherent for cities located in the western and the central parts of the country. The average value of the consolidated index of the assessment of city possibilities (an integral indicator that considers the possibility to express opinions freely, travel between city districts, impact the process of decision-making in the city, etc.) is determined. There is a positive correlation between this index and the volume of external mobility, i.e., the relative volume of external mobility is larger to cities where citizens admit a higher quality of life. The averaged over the year, an average number of trips which were made from every city is calculated, and for every trip, its distance is determined (by the road network). Also, the regularities of external mobility to cities with different sizes (the average length of trips changes within 39,0 – 56,5 km; 95% of trips are on the distance of 150–250 km; 99% of trips – on the distance of no more than 400–600 km). Obtained results will provide the opportunity to form further recommendations about improving the city's transport system, which should consider the daily volume of its visitors and the tendencies of its (system) change in case of improvement of the quality of life in the city).

Analysis of calculating level of service for pedestrians

In this paper, several methods of the assessment of pedestrian objects operation based on the level of service are reviewed. Today, there is a problem that should be assessed, particularly how pedestrian paths respond the level of service. Assessment of this level is the most widespread method of determination the objects` quality that relate to the pedestrian operations. Places, where a significant probability of conflict between different flows and their users, are often called intersections. Moreover, on such intersections, particularly with complex road conditions and on which the movement of cyclists, cars, and different vehicles is present, road users face with complicated situations when every of them should be sure in his safety and forecast further actions and decisions of other road users. The most widespread and generally accepted methods of assessment of level of service on pedestrian path, particularly: Highway capacity manual 2000 method, Australian method, method of the trip quality, Landice model and common approach analysis. Vehicles, signal delay, and interaction of pedestrians and cyclists were determined as the main factors that have impact on the level of service of pedestrians at the intersections. Analysis of different methods in the paper allows assessing and identifying the level of service determining the characteristics that could help in solving the questions concerning the comfort of pedestrian movement. In the range of these methods, the principles of vehicles movement and interaction with pedestrians are also reviewed. Other methods relate more to the design of the objects of pedestrian environment than factual movement of pedestrians. To form the whole understanding of the methodology of determination of the level of service of pedestrian objects, we should analyze and compare the values, obtained by different methods.

Capacity increasing of arterial streets with controlled motion

The problem of capacity increasing of arterial streets with controlled motion is investigated in this paper. For investigation, sections between intersections on the road network of Lviv city were chosen at their different length and roadway width with most saturated traffic. Methods of capacity increasing of arterial streets with controlled motion and factors that have impact on the capacity reduction are analyzed. Capacity of intersections at different volume-capacity ratios is determined. The distribution of average speed for sections between intersections of different length is built. It is established that on sections of medium length between signalized intersections and the high volume-capacity ratio, the speed of traffic flow does not reach maximum values. It is possible to increase the speed and the capacity of sections between intersections by increasing their length, sufficient for flow acceleration to the maximal constant speed and further braking before the intersection. To determinate the recommended speed of movement on arterial directions, road conditions are taken into account, which are formed with simultaneous impact of several factors: volume-capacity ratio of intersection in braking zone, volume-capacity ratio of intersection in acceleration zone, the number of lanes, the length of the section between intersections and the average speed of the traffic flow. It is determined that the average speed of traffic flow on short sections between intersections (the length less than 300 m) is 27 – 33 km/h, on sections of medium length – 35 – 38 km/h/ Such speed will allow to traffic flow reaching the line of constant movement in given road conditions. Conducted research allows taking into account road traffic conditions while justifying the calculating speed of traffic flow, in result of which capacity of arterial streets of controlled motion increases.

Influence of traffic flow intensity on environmental noise pollution

The modern urban environment, with the development of industry, the growth of the vehicle's number on the roads, and the increase in the density of buildings, is increasingly capable of negatively affect the health and well-being of the city's population. Among the factors influencing the environment is noise pollution, namely man-made noise - unwanted and harmful sounds created as a result of human activities. Today, noise is one of the most common factors of pollution among all others. The most common source of noise pollution is transport, including cars and trucks, buses, railways, airplanes, etc. The negative phenomenon of traffic noise is that almost everyone is greatly affected. This can often be accompanied by other harmful factors, such as vibration. According to scientific researches, noise can cause irritation under constant acoustic exposure. As a result, there are sleep disorders, decreased mental capacity, and the development of stress, and stress development in humans. Traffic noise is created from the operation of engines, the friction of wheels with the road surface, brakes, and aerodynamic features of vehicles, etc. In general, the level of traffic noise depends on such basic indicators as the intensity, speed, and composition of the traffic flow. Therefore, an important task is the study of traffic noise, its measurement, the establishment of appropriate dependencies, and further evaluation of the results. Knowing the level of noise generated by vehicles, further measures to reduce it are possible, such as redistribution of traffic flows on the road network, speed limits, improving the quality of the road surface, the use of basic means of reducing noise pollution, the use of noise protection devices, etc. Based on this, the negative impact of this phenomenon on the human body and the environment, in general, can be reduced.

The influence of degree of loading and load placing on steerability of vehicles

The methodology of research of the influence of the degree of loading, kinematic parameters of movement, and nonlinear power characteristics of elastic elements and shock-absorbers of the suspension system on their steerability on curved sections of the road is developed. The research is based on the equation of kinetostatics of the system of sprung-unsprung part and differential equations that relate the motion of the sprung part of vehicles. Concerning the last, they take into account both loading of a vehicle and nonlinear-elastic characteristics of shock-absorbers. For the case when elastic characteristics of shock-absorbers are described by degree or close to it dependence, the fluctuation of sprung part is described analytically. Their peculiarity is that the frequency and therefore dynamic force of wheels pressure on the bearing surface (road) depends on the amplitude. It is the last value and characteristics of the road surface that determine the main parameters of steerability and stability of the movement of wheeled vehicles along curved sections of the road. Taken together, the mentioned above allowed to obtain the dependence of the critical value of the dynamic angle of rotation of the steered wheels, as a function of the amplitude of longitudinal-angular oscillations, kinematic motion parameters, and the level of loading of a vehicle. It is established: - fluctuation of the sprung part significantly reduce the value of the limiting angle of rotation of the steered wheels along the curved sections of the road; - for the period of acceleration of the vehicle and the closer location of the center of gravity of the cargo transported to the tailgate, the limit value of the dynamic angle of rotation of the steered wheels is less; - the suspension system with the progressive law of change of regenerative force of elastic shock-absorbers in a wider range of change fluctuations amplitude of the suspended part satisfies ergonomic conditions of transportation. The obtained calculated dependencies can simultaneously be basic during the modernization of existing or the creation of new suspension systems in order to improve the main operation characteristics of wheeled vehicles