Design of Urban Public Transport Lines as a Multiple Criteria Optimisation Problem

This paper will describe a mathematical programming approach used for the line-planning problem in urban public transport. The input data include the transportation network in a city, O-D matrix of travel demand, and the set of available vehicles of specified transportation modes and types. The goal of line planning is to design the routes of lines and their frequencies. Supposing an initial set of lines has been proposed, the line-planning problem is formulated and solved as a multiple criteria optimization problem, where the criteria reflect the travelers’ demand for a high quality service, the operator’s interest in an effective service, and the environmental impact of the vehicles. The solution to this problem specifies the number of vehicles of the given mode and type operating on the lines. Lines, which are not assigned a vehicle, will not operate. At the same time, the solution specifies optimal passenger routes in the line network. Then an iterative process follows which computes new line frequencies using a discrete choice model to respect passengers’ behavior when they have multiple travel alternatives.