Title
Computing multi-modal journey plans under uncertainty
Abstract
AbstractMulti-modal journey planning, which allows multiple types of transport within a single trip, is becoming increasingly popular, due to a strong practical interest and an increasing availability of data. In real life, transport networks feature uncertainty. Yet, most approaches assume a deterministic environment, making plans more prone to failures such as missed connections and major delays in the arrival.This paper presents an approach to computing optimal contingent plans in multi-modal journey planning. The problem is modeled as a search in an And/Or state space. We describe search enhancements used on top of the AO* algorithm. Enhancements include admissible heuristics, multiple types of pruning that preserve the completeness and the optimality, and a hybrid search approach with a deterministic and a nondeterministic search. We demonstrate an NP-hardness result, with the hardness stemming from the dynamically changing distributions of the travel time random variables. We perform a detailed empirical analysis on realistic transport networks from cities such as Montpellier, Rome and Dublin. The results demonstrate the effectiveness of our algorithmic contributions, and the benefits of contingent plans as compared to standard sequential plans, when the arrival and departure times of buses are characterized by uncertainty.
Year
DOI
Venue
2019
10.1613/jair.1.11422
Hosted Content
DocType
Volume
Issue
Journal
65
1
ISSN
Citations 
PageRank 
1076-9757
0
0.34
References 
Authors
0
6
Name
Order
Citations
PageRank
Adi Botea169862.87
Akihiro Kishimoto221628.42
Evdokia Nikolova335131.03
Stefano Braghin43810.43
Michele Berlingerio551028.92
Elizabeth Daly602.37