The rational operation of the urban transport line network by minimisation of the needed vehicles

Abstract

The construction of the urban transport line network is one of the fundamental problems in the traffic practice. Efficient functioning of the public mass transportation supported from the public sources in the towns is more urgent at present, when the individual automobile traffic leads to congestions in central parts of the cities. The demand to increase the culture of travelling in the public mass transportation requires, however, substantial costs. Therefore it is necessary to solve the balance between the inhabitants´ requirements and the economy of the transportation system. The operation of the public mass transportation must be rational; the vehicles must not show unreasonable waiting times, etc. One of the possible ways how to rationalise the public mass transportation is to minimise the number of vehicles in operation complying with the requirements of the travellers. The paper deals with the problem of minimising the number of vehicles needed to operate the lines of the public mass transportation network. To solve this problem the methods of linear programming are used. There are four mathematical models described in which the vehicles are assigned to the individual lines. The models arise from the mathematical model PRIVOL [4], and they vary from this model especially by the variety of the rolling-stock the transport company has at disposal. By means of the constructed models a number of numerical experiments concerning the network corresponding to a medium-sized town were performed using the four constructed models. These numerical experiments demonstrated the functionality of the designed models. The main contribution of the presented modifications of the original model PRIVOL consists in the fact, that instead of the optimal number of seats the new models are able to directly find an optimal number of vehicles needed to operate the particular lines to meet the expected demand of the passengers. That way the proposed approach allows to objectify the decision making of the transport company concerning the allocation of vehicles to the network lines.