CC BY
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УДК: 656.02 ГРНТИ: 73.43.61 DOI: 10.15643/jscientia.2017.12.001
DEVELOPMENT OF A MODEL OF THE ADAPTIVE CONTROL OF PASSENGER FLOWS IN THE CITY'S ROAD NETWORK
D. G. Kbilashvili, G. A. Lekveishvili, P. G. Gogiashvili, J. T. Chogovadze, V. V. Dograshvili
Akaki Tsereteli State University 59 Tamar Mepe Str., Kutaisi 4600, Georgia
S3 Lekveishvili Gocha - g.lekveishvili@gmail.com
The paper describes the conditions of the effective operation of urban passenger transport. Also, there have been explored the parameters of passenger flows on the bus routes, and the local areas with high intensity and density have been identified. The paper also presents the pattern of daily and hourly distribution of passenger flows on these areas, according to which a model of the adaptive control of transport has been developed, as well as the parameters of the effective functioning of this model have been assessed.
Keywords: passenger flow, adaptive control, intensity, demand-supply, urban transport.
Funding: This work was supported by Shota Rustaveli National Science Foundation (SRNSF) [№ 217764, Adaptation of Disabled People in the Logistics System of Passenger Transport]
РАЗРАБОТКА МОДЕЛИ АДАПТИВНОГО УПРАВЛЕНИЯ ПАССАЖИРСКИМ ПОТОКОМ В ГОРОДСКОЙ ТРАНСПОРТНОЙ СЕТИ
Д. Г. Кбилашвили, Г.А. Леквеишвили, П. Г. Гогиашвили, Д. Т. Чоговадзе, В. В. Дограшвили
Государственный университет Акакия Церетели Грузия, Кутаиси. 4600, ул. Тамар Мефе, 59
El Леквеишвили Гоча Анзорович - g.lekveishvili@gmail.com
В статье рассмотрены условия эффективного функционирования городского пассажирского транспорта. Проведен анализ внутренних и внешних факторов, влияющих на транспортную систему, которые оказывают значительное воздействие на устойчивость городского транспорта. Исследованы параметры пассажирских потоков на автобусных маршрутах и выявлены локальные участки с высокой интенсивностью и плотностью. Представлены закономерности дневного и почасового распределения пассажирского потока на этих участках, в соответствии с которыми разработана модель адаптивного управления транспортом. Произведена оценка показателей эффективности функционирования модели.
Ключевые слова: пассажирский поток, адаптивное управление, интенсивность, спрос-предложение, городской транспорт.
Финансирование: Работа выполнена при финансовой поддержке Национального научного фонда Шота Руставели [Грант №216752, Адаптация лиц ограниченными возможностями в логистической системе городского транспорта]
The efficient functioning of urban passenger transport depends in substantial part on ensuring the principle of balancing the supply and demand of transport services [1, 2], whose practical implementation is much too complicated because of a random nature of the population's demand for urban transport services. Based on this, in addition to addressing the objective of modernizing the existing route system or designing the advanced route system by using real data on statistical characteristics of passenger traffic, the objective of operational design and control of routes within the current system has moved center stage.
In recent years, some negative trends have emerged in the field of urban passenger transport services, which were conditioned by the effect of incalculable internal and external factors influencing the system [3, 4]. Such external factors are as follows:
- high degree of the unevenness of the distribution of the passenger traffic between the routes of urban transport and throughout the length of particular routes;
- high degree of the unevenness of the distribution of passenger traffic in accordance with time parameters (seasons of the year, weekdays, day hours);
- high intensity of using private passenger cars under conditions of the dramatic increase in the motorization level;
- the difficulty of forecasting the reduction in passenger traffic under conditions of the wide range of variation of the intensity of using private passenger cars;
- the difficulty of forecasting the reduction in the speed of transport flow and variation of the duration of delays during travels;
- a low level of the organization of road traffic adapted to the parameters of the urban road network and the use of the management systems;
- the absence of a flexible parking system for the passenger cars, etc.
The internal factors include:
- a low level of the organization of a road-transport complex and the effective functioning of the management systems;
- an insufficient level of the awareness for making the right and timely managerial decisions;
- an insufficient level of the management of transport infrastructure;
- an insufficient level of the operational management
of the carriage of passengers on routes in the city in various transport situations, etc.
Due to a negative impact of mentioned factors, the problems had arisen, such as:
- the decline in the quality of urban transport services due to the duration of travel and the overload of the bus;
- increased obstructions and failures in the carriage of passengers on routes in the city in various transport situations;
- the inefficient use of the active resource of an active resource of the motive power;
- the decline in the cost-effectiveness of the urban transport functioning due to the reduction in passenger traffic;
- a low level of competition of the carriage of passengers by urban transport in comparison with the carriage by private passenger cars, due to the decline in the quality of service, etc.
In order to resolve these problems, there have been developed innovative approaches and the practical models, the use of which allows for providing passengers with proper transport services operatively - at the "right place' and in the "required amount". Among them, of particular interest are the following approaches:
- redistribution of various capacities between and on the routes during and between peak hours in the city by ensuring the observation of the regular interval;
- selecting the rational structure and optimal regimes of the motive power when using the buses of different capacities on the urban bus routes by the criterion of the minimum accumulated time spent on travel.
These have been the particularly acute problem for the urban passenger transport of Kutaisi City over the past 5 years, which were mostly caused by a high motorization level and the overload of the road network. Analysis of a sharply growing trend in the motorization level reveals that the number of private passenger cars is increased from 40 thousand to 66 thousand. At the current stage, the motorization level in the city reached 0.37 cars per person (the total number of residents in Kutaisi City is 178 thousand people), to this is added the number of cars entering the city within 24 hours from the districts and villages located within administrative boundaries of the city, which varies between 15...20% of the total number of cars registered in Kutaisi City. In addition to this, the city's roads with a transit function have partially preserved this function, despite the fact that just 6 km away from Kutaisi City, there is located the central motor trunk road of Georgia, which further increases the number of entered cars by 5.6%. An unpredictable growth rate of the motorization leveled to the overload of the urban road network, and as a result, to the complication in the regulatory environment of traffic flows. Despite the fact that a significant investment has been made in Kutaisi City for the purpose of developing road-transport infrastructure over the past three years, the quantity of work performed has not yet met the establisher requirements. Proceeding from this circumstance, along with high intensity of using private passenger cars, parking of the passenger cars has become a particularly acute problem. The parking system existing in the city cannot satisfy the level of the requested services, due to which there has been a marked increase in the cases of parking without permission on roadways, especially during peak hours that resulted in reduced traffic capacity of roads.
For the purpose of assessing a negative impact of the complicated transport situations in Kutaisi City on operability of urban passenger transport, in 2016-2017, the authors
carried out studies of the main characteristics of the existing route system.
At the initial stage of these studies, on the existing routes of the main directions (communications) of passenger traffic during peak hours (8...10 a.m. 12...2 p.m.; 5...7 p.m.), there were carried out studies of the parameters of passenger traffic by using tabular method of field studies, which allows for obtaining the required quantity of information by the counters in the passenger compartments along the entire length of route. During the experiments, these counters were equipped with the special observation tables, which, along with data on the bus, contained time of the bus's turn to enter service, bus service number (direct or backing-up), time to enter service and the bus stop points. At every stop, the counters entered data on the number of the passengers who had entered the bus and exited from the bus into the appropriate boxes of table, as a result of which, they carried out calculation of the parameter of filling the bus on the main space intervals of routes. Accounting and registration of the movement of passengers were carried out by each counter, and the obtained results they processed together with a group leader. This tabular method can be also used during the process of massive and elective studies.
The parameters of passenger flows on the particular routes have been explored by seasons of the year, weekdays and day hours.
Studies of passenger flows by seasons of the year were started in January 2016 and completed in the month of August 2017. The studies were carried out in the entire route network of the city, and particular attention was paid to the local sections with high intensity and density of passenger flows. During the process of conducting these studies, there were used the modern methods of design of experiments [5].
In management of demand for urban transport services, of particular importance is regulation, which is necessary for demand balancing the demand by the periods of 24 hours, weekdays, route directions and sections. The non-uniformity of demand is high enough, thus the non-uniformity factor of passenger flow by the periods of 24 hours, weekdays, route directions and sections varies from 1.1 to 2.5. Such non-uniformity of demand requires its regulation for the purpose of a more even distribution of passenger flow and a more economical use of the motive power of urban passenger transport. Based on the analysis of the results of studies, there have been assessed the parameters of the unevenness degree of hourly distribution of passenger flows in the route network of Kutaisi City, for which we have used coefficient of the hourly maximum, which is determined using the following formula:
kT =
Ami
A
(1)
where A „ - the number of passengers transferred
max, 1 ' °
on route during peak hours; An - the number of passengers transferred on route throughout the working day for 1 hour on average.
In our case, coefficient of the hourly maximum is kT = 2.5 By assessing the influence of seasons of the year on the dynamics of passenger flows in the route nerwork, it has been established that the high inetsnsity and density of passenger flow occur in month of October or, but by weekdays - on Tuesday [6, 7]. In addition, two sections A and B with highest intensity have been identified in the route network of Kutaisi City (Fig. 1).
Fig. 1. The values of passenger flows in the route network of Kutaisi City
There have been determined the values of passenger flows towards the delivery points 1, 2 and 3. The passenger flow towards the delivery points 2 and 3 is overloaded too much and requires undertaking the operational measures for traffic relief. Fig. 2 illustrates the diagram of the hourly distribution of passenger flow on the A section, according to which, the number of passengers transferred from 8 a.m. to 10 a.m. was up to 5 thousand people, whose transportation without delays under existing operating conditions of urban transport is impossible.
Proceeding from the above, it has become necessary to create the adaptive control scheme of urban transport (Fig. 3).
Fig.3. The adaptive control scheme of urban transport A - Bus stop: S - the area occupied by passengers; MTE-motor transport enterprise,CCR - centralized control room; ATCS - additional traffic control station.
The process of introduction of the additional transport units for a motor transport enterprise leads to additional costs by calculating on transportation of passengers at a distance of 1 km (Fig. 4, Diagram 3).
However, the introduction of the additional transport units has also its positive sides as follows: 1) The quality of transport services is improving (by reducing the accumulated time for spent on travel and by upgrading the travel comfort); 2) the main vehicles operate without overloading that allows for reducing technical costs and for increasing the vehicle's resource (Fig. 4, Diagram 3).
B50 1000
h 700
-I 500
I _ ™ 500
III.
6 7 B 9 10 11 13 13 14 13 16 17 18 19 20 21 I»? 23
Fig. 2
The adaptive management scheme operates on the following principle: the main transport units are supplied from a motor transport enterprise to the network in accordance with standardized schedule, but the additional transport units are supplied to the section with high intensity of passenger flow, where there is also located the additional traffic control station (ATCS). The ATCS receives primary information about an acute increase in passenger flows during peak hours from the driver, and besides, at stations (stop points) with high passenger flows, there is installed the information-intelligent system (with surveillance), which analyzes information about the area of the section S occupied by passengers. This information is delivered to the ATCS and the centralized control room (CCR) [7].
By the area of the section S occupied by passengers (4-5 passengers on 1 sq. m), the centralized control room determines the value of the expected passenger flow, and informs the ATCS about the need for the additional transport unit. The number of the additional transport units and their delivery time are determined in accordance with the expected passenger flow.
Fig. 4. The dependence of vehicles repair and operation costs on operating conditions:
1 - Operation of vehicles between peak hours;
2 - Operation of vehicles during peak hours;
3 - Operation of vehicles during peak hours, under conditions of using the additional transport units.
It has been established that in the existing system, at the sections overloaded with passenger flows due to the overload with the buses during peak hours, the operation cots are increased almost by 20%, but technical service costs are doubled, in comparison with operation between peak hours. When introducing the additional transport units, the operation costs were increased by 10...15%, but technical services costs were reduced almost by 60%, and at the same time, the accumulated time spent on travel was reduced and the travel comfort was upgraded.
Conclusions
1. In the design of the city's route network, when the rational numbers and optimal traffic intervals of the buses on rote are selected, it is impossible to avoid the overload with passenger flow at some local areas. To cope with this, it is necessary to introduce the components of operational transport control in the unified control system of urban transport;
2. To avoid interruptions of transport services at the local areas overloaded with passenger flows, there has been developed the adaptive scheme of the active reservation of urban transport, where the introduction of the additional transport units is carried out directly on the overloaded sections on the basis of data from the information-intelligent systems;
3. When using additional transport, there have been assessed the economic indicators of service, particularly the transport costs during peak hours are increased almost by 20%, but the technical service costs are doubledare doubled, in comparison with operation between peak hours. When introducing the additional transport units, the operation costs were increased by 10...15%, but technical services costs were reduced almost by 60%.
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Received 23.10.2017
