Abstract

TRA 2018, 7th Transport Research Arena, Vienne, AUTRICHE, 16-/04/2018 - 19/04/2018; The decrease of road accidents these recent years has induced the interest to work on road driving hazardous situations called incidents. Otherwise, in France, users of Power Two-Wheeler (PTW) are less than 2% of traffic but, in the accidents represent 43% of serious injuries and 23% of killed persons. This paper provides a descriptive analysis of the incident database acquired during one year with a fleet of 30 motorcycles and a few cars equipped with an Event Data Recorder. The objective is to acquire knowledge on their accident mechanisms and improve their safety. For the 395 motorbikes' and 32 cars' incidents collected, the analysis of the triggering criteria, the dynamics parameters and the road configurations illustrates the great variety of situations and shows how the behaviours of riders are different from those of car drivers. The investigations on the causes of the incidents indicate that the more frequent cause is the driver (94%), but the road environment and the other road users could have been involved in 40% of the cases each.; La baisse du nombre d'accidents de la route de ces dernières années a amené les chercheurs à s'intéresser aux situations de conduite critiques que l'on appelle des incidents. Par ailleurs, en France, les usagers de deux roues motorisés représentent moins de 2% du trafic, et pourtant 43% des blessés graves et 23% des décès sur la route. Ce papier propose une analyse descriptive de la base de données des incidents recueillis pendant un an sur une flotte de 30 motos et quelques voitures équipées d'enregistreur de données de la route. L'objectif était d'acquérir des connaissances sur leurs mécanismes d'accident et d'améliorer leur sécurité. Pour les 395 incidents de 2-roues et les 32 incidents de voitures, l'analyse des critères de déclenchement, des paramètres de la dynamique du véhicule et des configurations de la route illustre la grande variété des situations et montre les différences de comportement des motards par rapport aux automobilistes. Les investigations sur les causes des incidents indiquent que la cause la plus fréquente est liée au conducteur, mais l'environnement et les autres usagers pourraient être impliqués dans 40% des cas.

Abstract

We study the problem of finding an optimal itinerary to travel from a starting location to a destination location using public transport, where we allow travelers to alternate rides with (short) walks. The main difference with previous research is that we take all possible walks that a traveler can make into consideration. This large number of possible walks poses a potential computational difficulty. However, in this paper we derive theorems for identifying a small subset of walks that only need to be considered. These results are embedded in a solution algorithm, which is tested in a real-life setting for bus transportation in a medium sized city. An extensive numerical study leads to encouraging results. First, only 1% of all possible walks needs to be considered, so that the optimal itinerary can be determined very efficiently. Second, allowing walks has considerable benefits; reducing the travel time in about 6% of all randomly generated examples by more than 10% on average. (C) 2013 Elsevier Ltd. All rights reserved.