ECOPT organizes a workshop on March 13, 2025, at the Erasmus University Rotterdam.

Speakers and program

The speakers in this workshop are:

• Evelien van der Hurk - DTU (Technical University of Denmark)
• Sander Van Aken - Flix SE (Germany)

The program is as follows.

Venue: The event takes place on campus Woudestein of Erasmus University Rotterdam, specifically in the Van der Goot-Building, Room M1-19 (Athens). Directions on how to get to the campus and a map of the campus can be found here. 

Registration: Participation in the workshop is free. However, only a limited number of places are available. Please register using this form.

Evelien van der Hurk: Optimal Lineplans with frequency dependent travel times, and towards Demand Elasticity

At the core of any public transport network is the lineplan, which defines the set of directly connected stops, as well as the in-vehicle time between them. Moreover, every line needs to be associated with a frequency. It is the combination of frequency and line that will define which routes passengers may find most attractive: a direct or faster route at a low frequency may be less preferable to a route with a small detour, or even a transfer, that operates at a high frequency. Therefore, when one aims to design a lineplan with minimal weighted travel time, it is of great value to take frequency-dependent route costs into account.
In this talk I will present our results for such a lineplanning model that is able to take a large number of frequencies, e.g. 20 or more options per line, into account. It allows to specify path costs as any function of the in-vehicle time and associated lines. As a result, we also experiment with the introduction of a form of demand elasticity; where passengers are only traveling in the designed network when their frequency-dependent path costs are below an upperbound. The upperbound may for example be defined by an alternative mode.
As models that include frequency-dependent paths typically are very large, we propose a new exact algorithm that allows to solve medium-sized instances within reasonable computation time. 

Sander Van Aken: Building tailored OR-powered software solutions to support Flixbus’ network planning and boost profitability

Flix has rapidly become a global player in the long-distance passenger transportation market, operating in 44 different countries across 4 continents as FlixBus, FlixTrain, Greyhound (North America) and Kamil Koc (Turkey). Being a commercial company, thoroughly matching supply and demand is a key element for sustainable growth and profitability for both Flix and our mobility partners, who operate the network. Network planners create timetables, vehicle and crew schedules with the aim to build these profitable networks. 

Our tech teams support them with a range of internally developed tools, amongst which a granular PAX and revenue-forecasting model, and a product for bus and driver schedule optimization. In this talk, we will first show how we deal with the real-world complexity of our global business model, and how we turn this into our advantage to deliver pragmatic OR solutions.

Beyond merely focussing on cost-efficient supply, planners anticipate and adapt to highly seasonal demand and revenue. With a particular planning methodology, they strike a good balance between perfectly fitting supply to demand, and limiting network complexity. We will share a glimpse on our current journey in connecting the forecasting models with seasonality optimization algorithms.