Problem Statement

Public transport will continue to play an important role in the future to transport a large number of people quickly, cost-effectively and in an environmentally friendly manner. It is therefore desirable to plan transport services in such a way that they offer adequate alternatives to private transport. In order to plan such a transport offer, the greatest possible freedom in optimization and a realistic evaluation is essential. A restriction of freedom is for example a system-wide frequency of all offered lines. The evaluation of transport offers or the feasibility is usually done with the help of transport demand models. Although the currently available models can partially represent disturbances, e.g. buses in traffic jams or fluctuations in travel time, they cannot represent the corresponding reactions of passengers and the operator to these disruptions. If the reactions are neglected in the evaluation, the effects may be much stronger.

Objective

In this project, we want to consider an integrated planning approach on public transportation to improve the quality of public transportation systems with regard to customer satisfaction and system costs. Additionally, we want to derive solutions that are robust with respect to delays. Our goals are:

• a better coordination of line planning, timetabling, vehicle and driver schedules by optimizing the public transportation system integratedly instead of the usual sequential optimization approach
• a better focus on the customers: lines and timetables should be as attractive as possible for the passengers. Thus, we work on routing in multimodel networks and integrating realistic demand models in the optimization problems.
• a better delay management as well as the development of robust solutions by considering typical delays occuring in the operating procedure during the planning process

Using approaches of discrete optimization, algorithm engineering and public transportation simulation, we work on innovative procedures for improving the planning process in public transportation. The achieved results are illustrated on different demonstrators, e.g. a large realistic example case.

Methods

The research group combines approaches of optimization, algorithm engineering and public transport simulation.

The IfV investigates three research questions within this project.

First, the reaction of passengers to disruptions is empirically investigated using various surveys. First, the decision-making scope of passengers in public transport is investigated with the help of interviews and a revealed-preference survey. This serves as a preparatory step for a stated choice survey, in which test persons in various disruption situations are asked to select one of several alternatives. Based on this, a decision model for the behavior of passengers in case of a disruption is to be developed.

Second, both empirically and data-driven, the reaction of operators to disruptions in public transport will be investigated. For this purpose, the behavior of dispatchers of different transport companies will be surveyed with interviews and a revealed-preference survey. Subsequently, data from the intermodal transport control system of a transport company will be examined with regard to the decisions actually made. Based on these data, a decision model will be developed and integrated into the simulation of public transport. This extends the public transport simulation developed in the first phase of the research project.

Third, the boundary conditions for the planning of services are empirically investigated. The survey is to be conducted online and will solve the question of whether a frequency is desirable for all or certain groups of passengers. Different forms of clock cycles will be considered (e.g. system clock, line clock, partial clock thinning, completely clock-free).