Online design of dynamic networks

TL;DR

This paper introduces an online, dynamic network design method using Monte Carlo Tree Search, demonstrated on a public transport scenario with stochastic demand, outperforming traditional vehicle routing approaches.

Contribution

It presents a novel online network design approach for dynamic environments, enabling real-time network construction to adapt to stochastic changes.

Findings

The method effectively designs dynamic public transport networks in real-time.

It outperforms state-of-the-art VRP methods in stochastic demand scenarios.

Structured network building improves system performance over isolated trajectory extensions.

Abstract

Designing a network (e.g., a telecommunication or transport network) is mainly done offline, in a planning phase, prior to the operation of the network. On the other hand, a massive effort has been devoted to characterizing dynamic networks, i.e., those that evolve over time. The novelty of this paper is that we introduce a method for the online design of dynamic networks. The need to do so emerges when a network needs to operate in a dynamic and stochastic environment. In this case, one may wish to build a network over time, on the fly, in order to react to the changes of the environment and to keep certain performance targets. We tackle this online design problem with a rolling horizon optimization based on Monte Carlo Tree Search. The potential of online network design is showcased for the design of a futuristic dynamic public transport network, where bus lines are constructed on the fly to better adapt to a stochastic user demand. In such a scenario, we compare our results with state-of-the-art dynamic vehicle routing problem (VRP) resolution methods, simulating requests from a New York City taxi dataset. Differently from classic VRP methods, that extend vehicle trajectories in isolation, our method enables us to build a structured network of line buses, where complex user journeys are possible, thus increasing system performance.