METHODOLOGY FOR DETERMINING PARAMETERS OF DESIGN VEHICLE, TAKING INTO ACCOUNT CONDITIONS OF ARCTIC ZONE OF THE RUSSIAN FEDERATION

Over the past decades, the automotive market has been growing and developing rapidly. Vehicles are constantly modified: their geometric parameters (length, width, height, etc.) and dynamic parameters (power, acceleration speed, etc.) change. For the design and construction of the roadway, as well as subsequent calculations in the field of traffic management (flow saturation, mandatory control, etc.) in accordance with the regulatory documentation, geometric and dynamic parameters of the design vehicle are used, the parameters of which are determined on the basis of Soviet cars of the 80s. As a result of vehicles changes and modifications, it is necessary to update and perform additional calculations to determine the parameters of an improved design - calibrated vehicle. The main purpose of the study is to determine the parameters of the design – calibrated vehicle for performing calculations in the field of construction and traffic management. In the course of the research presented in this article, the analysis of statistical data regarding the best-selling light vehicles, as well as the variability of the geometric parameters of vehicles were determined. Based on all the completed tasks, the result of the work is determination of the design - calibrated vehicle for Arctic zone of the Russian Federation, which will be subsequently used for the design and construction of the roadway and calculations in the field of traffic management.


INTRODUCTION
Arctic zone of the Russian Federation (AZ RF) is the northern territories of the European and Asian parts of the Russian Federation located along the coast of the Arctic Ocean seas. It occupies the largest area of the Russian Federation land part (4,774.02 thousand km2), having the longest maritime border of Russia. The AZ of the Russian Federation includes 9 regions: 4 of them are constituent territories of the Russian Federation: Chukotka Autonomous Region, Yamalo-Nenets Autonomous Region, Nenets Autonomous Region, Murmansk Region and 45 municipal districts of 5 constituent territories of the Russian Federation: The Republic of Karelia, the Komi Republic, Arkhangelsk Region, Krasnoyarsk Territory, the Republic of Sakha (Yakutia). The transport system of Arctic zone is developing slowly and unevenly. In the western part of the AZ of the Russian Federation, motoring highways connect only large settlements and industrial centers of Murmansk and Arkhangelsk Regions with the center of the European part of the Russian Federation. Distinctive features of RF AZ transport system include the following: relatively low density of land routes or their absence; seasonal nature -in particular, transportation is possible by water transport during the navigation period -from June to September, by road transport during the winter season -from December to March; in some regions, aviation or sea transport is the basis of life support. Due to its vast territories, each region of Arctic zone of the Russian Federation has its own economic zone, which differs from any other zone by distinctive properties and characteristic features. Transport is the prime factor in maintaining the competitive ability of industrial enterprises of AZ of the Russian Federation, it performs the main social function -ensuring life quality and population mobility of the Russian Federation AZ. The functioning, economic growth and development of the entire region, country including Arctic zone depend on the transport system [1][2][3]. The basis of the economy of Arctic zone of the Russian Federation is the mining industry, while in separate regions of AZ of the Russian Federation various areas of industry prevail, for example: transport and defense complex in Murmansk Region, forest industry in Arkhangelsk Region, etc. Various types of activities and industries have an impact on the formation of the transport system, which as a result forms a heterogeneity of vehicles types of used in a particular region of the AZ of the Russian Federation. The purpose of the study is to determine the parameters of a designed -calibrated vehicle for performing calculations in the field of traffic management and design of highway crossings, junctions.

METHODOLOGY
When assessing the heterogeneity of the traffic flow in the classical way, cars, trucks and buses are distinguished.  Traffic, trucks traffic along the central streets of cities, as well as entry into the city itself is prohibited. Therefore, passenger and fixed-route vehicles predominate in traffic flows in cities [4,5]. The analysis of official statistics confirms the heterogeneity of vehicle types and reflects data on the distribution of the main types of vehicles in the traffic flow. The growth in the number of automobile parks in the Russian Federation is increasing every year, and the share of light vehicles in the flow is about 87% of the total number of vehicles (Fig.1).

Figure 1: Distribution of the main types of vehicles in the Russian Federation
It is known, that the design and construction of roadway widenings, crossings and junctions, and subsequently, the organization of traffic is impossible without taking into account the geometric data of the design vehicle, which is taken on the basis of the analysis of the traffic flow composition [6][7][8][9][10]. In Russia, for calculation of mandatory control, constant reduction coefficients of the design vehicle are used, developed based on the geometric characteristics of the first domestic cars, such as: Moskvich 407, Microlitre M-21 "Volga", M-20 "Pobeda", ZIL-11. However, every year the level of world and Russian vehicle fleets increases, both technical and geometric parameters of vehicles change, which have a direct impact on design of transport system and traffic management [11,12]. In this regard, it is necessary to monitor the development and modification of vehicles and periodically update the reduction coefficients of the design vehicle. Within the framework of this study, the tasks are to perform analysis of statistical data, that includes indicators of the best-selling light vehicles in individual subjects of Arctic zone of the Russian Federation and Russia as a whole.    Having analyzed the best-selling brands of light vehicles in the AZ of the Russian Federation and the Russian Federation over the past five years, their most popular and best-selling models were determined. In Arctic zone, such models of light vehicles of various cross-country capacity as Lada Granta, UAZ Patriot, Kia Rio, Hyundai Solaris and Toyota Hilux are in great demand. As for Russia, the most common are: Lada Granta, Kia Rio, Hyundai Creta, Renault Duster, Volkswagen Polo.

EXPERIMENT
Within the framework of this research, the next task is to determine the geometric parameters of the design vehicle for Arctic zone of the Russian Federation. In consequence of the statistical data analysis of sold cars in the AZ of the Russian Federation and Russia, it is possible to determine the difference in the geometric parameters of vehicles, namely, the finding of overall parameters that will be taken into account in the design vehicle when performing transport calculations in the field of traffic management [13,14]. The geometric parameters of the best-selling light vehicles in the AZ of the Russian Federation and Russia were determined (Table2). As a result of a complete analysis of the technical characteristics of light vehicles, the difference in the overall vehicle parameters is clearly visible. The overall dimensions of vehicles in Arctic zone vary in length of the vehicle within 4115 mm -5260 mm, width of 1700 mm -1900 mm, and turning radius is 5.2 m -5.62 m, for the Russian Federation: vehicle length is within 4268 mm -4483 mm, width of 1700 mm -1804 mm, and turning radius is 5.2 m -5.5 m. As we can see, the overall parameters of vehicles operating in Arctic zone differ from the overall parameters of Russia vehicles. Taking into account the existing fluctuations in overall parameters indicators, we will determine the main characteristics of design vehicle for the AZ of the Russian Federation and Russia by finding the arithmetic mean value. The arithmetic mean is calculated according to the formula: where xi -individual values of the variable feature, so-called variants; n -is the number of units of the population. In consequence of the arithmetic mean calculation, the main values of design cars parameters were obtained (Table 3). There is a difference in the readings of the geometric characteristics of desigh vehicles for Arctic zone and Russia, amounting to a deviation of 6%.

ANALYSIS
As a result of the research, it is possible to develop an algorithm that allows determining the geometric parameters of the design vehicle for Arctic zone of the Russian Federation, which will be taken into account in the design and construction of roadway widenings, crossings and junctions, as well as subsequent calculations in the field of traffic management and accident examination [15][16][17][18][19][20][21] (Fig.4).

DISCUSSION
Since the design and construction of the roadway, as well as subsequent calculations in the field of traffic management (saturation flows, forced control) are determined on the basis of the parameters of the design vehicle, which is accepted and approved in the main regulatory documents, but the car park is constantly changing -vehicles are being modified, it is necessary to constantly update the basic geometric characteristics of the design vehicle. Also, in different zones of the Russian Federation, depending on the location of the zone and traffic conditions, vehicles in the stream differ from each other, it is necessary to take into account these factors and determine the estimated vehicle for individual zones of the Russian Federation. On the example of the Arctic zone of the Russian Federation, this study shows the difference in the values of the geometric parameters of the design vehicle of this zone from the rest of the zones of the Russian Federation as a whole, the deviation is 6%. For the calculated vehicle of the RF zones, it is proposed to introduce such a concept as a calibrated vehicle -this is a vehicle with average parameters of vehicles that are most often encountered in the traffic flow.

CONCLUSIONS
In the course of the study, the following results were obtained: 1. The most common car in the traffic flow is installed -passenger car, which is more than 80%; 2. The main brands of passenger cars most often found in the flow for the Russian Federation and its Arctic zone are identified, which differ depending on the territory, which is explained by the presence of certain economic costs and are associated both with the level of income of the population and the territory itself. 3. One of the distinguishing features of the considered vehicles is concretized -overall parameters and the limits of their change are determined. 4. A mathematical model has been developed for calculating the parameters of a calibrated vehicle both for the Russian Federation and for the Arctic zone, as a result of which a difference of 6% has been determined, which must be taken into account when performing survey work -construction, reconstruction, reorganization and organization. 5. An algorithm for calculating the parameters of a calibrated vehicle has been developed and promising ways for further research have been identified.