3 research outputs found
Railway traffic disturbance management by means of control strategies applied to operations in the transit system
Railway systems in metropolitan areas support a high density of daily traffic that is exposed to different types of disturbances in the service. An interesting topic in the literature is to obtain action protocols in the presence of contingencies which can affect the system operation, avoiding the propagation of perturbation and minimizing its negative consequences.
Assume that, with a small margin of time (e.g. one day), the decision-maker of the transportation network is knowing that a part of the train fleet will become inoperative temporarily along a specific transit line and none additional vehicle will be able to restore the affected services. The decision to be taken in consequence will require to reschedule the existing services by possibly reducing the number of expeditions (line runs). This will affect travellers who regularly use the transit system to get around. Consider that the decision-maker aims to lose the least number of passengers as a consequence of
having introduced changes into the transit line. A strategy that could be applied in this context is to remove those line runs which are historically less used by travellers without affecting the remaining services. Another alternative strategy might be to reschedule the timetables of the available units, taking into account the pattern of arrivals of users to the boarding stations and the user behavior during waiting times (announced in situ).
The aim of this work consists of assessing the strategy of train rescheduling along the current transportation line when the supply must be reduced in order to reinforce the service of another line, exploited by the same public operator, which has suffered an incidence or emergency.Ministerio de Economía y CompetitividadFondo Europeo de Desarrollo Regiona
An optimization model for line planning and timetabling in automated urban metro subway networks
In this paper we present a Mixed Integer Nonlinear Programming model that we
developed as part of a pilot study requested by the R&D company Metrolab in
order to design tools for finding solutions for line planning and timetable
situations in automated urban metro subway networks. Our model incorporates
important factors in public transportation systems from both, a cost-oriented
and a passenger-oriented perspective, as time-dependent demands, interchange
stations, short-turns and technical features of the trains in use. The incoming
flows of passengers are modeled by means of piecewise linear demand functions
which are parameterized in terms of arrival rates and bulk arrivals. Decisions
about frequencies, train capacities, short-turning and timetables for a given
planning horizon are jointly integrated to be optimized in our model. Finally,
a novel Math-Heuristic approach is proposed to solve the problem. The results
of extensive computational experiments are reported to show its applicability
and effectiveness to handle real-world subway networksComment: 30 pages, 6 figures, 9 table