6 Novembre 2017

13h30 Etienne Come, Ifsttar/Cosys/Grettia.
Titre. Smart card data for mobility analysis : some results from the mobilletic project.
14h15 Hassan Mahdavi, Ifsttar/Cosys/Grettia.
Titre. Transit Route Implementation and Performance Management Tool (Transitmath).
15h00 Pause Café.
15h15 Hugo Badia.
Titre. Urban shape and optimal design of bus networks: from theory to application in Barcelona.
16h00 Sheng Li, Lvmt.
Titre. A model for urban public transport design : theory and application to the Parisian Region case.

29 Septembre 2017

Le séminaire a accuielli la chaire ENPC-IFM (IFM: Ile-de-France Mobilités, ex STIF).

[Chaire ENPC-IFM] Conférence "Simulation dynamique des trafics en transport collectif" le 29 septembre 2017 à la Cité Descartes.
La Chaire« Socio-économie et modélisation des transports collectifs de voyageurs en milieu urbain » est un partenariat décennal entre Ile de France Mobilités (le nom de marque du STIF) et l'ENPC.
Son objectif principal est de développer des modèles de simulation et des méthodes d'évaluation socio-économique pour la planification des transports de voyageurs en milieu urbain.
Chaque année, la Chaire tient une "conférence anniversaire" destinée aux opérateurs et aux planificateurs, aux ingénieurs et aux chargés d'étude ainsi qu'aux chercheurs.

Le programme est disponible ici .

19 Juin 2017

14h00 Guilhem Mariotte, Ifsttar/Cosys/Licit. Slides
Titre. Modeling traffic flow at the network scale with multi-reservoir systems using the MFD.
Résumé. Over the past decade, the Macroscopic Fundamental Diagram (MFD), relating the mean flow vs the mean density of a given urban area, has appeared to be a powerful tool to describe traffic states at the network level with few implementation and computational efforts. Many studies (e.g. Knoop & Hoogendoorn, 2014, Yildirimoglu & Geroliminis, 2014, Yildirimoglu et al., 2015, Haddad, 2015) have notably used MFD-based traffic simulators for several applications, like traffic state estimation, perimeter control or assessing routing strategies at a large scale. Their modeling approaches take advantage of the multi-reservoir representation of a city, where the dynamics of each urban subregion is described by the single reservoir model of Daganzo (2007). This framework, also referred as the "accumulation-based model", assumes that the reservoir outflow is proportional to the circulating flow inside the zone. However, while being acceptable in slow-varying conditions, this hypothesis may be too restrictive when the demand evolves too fast as shown by Mariotte et al. (2017). An idea, initially proposed in Arnott (2013), has been exploited in Daganzo & Lehe (2015) and then Lamotte & Geroliminis (2016) to design a "trip-based" formulation of the MFD model. This approach considers that all users travel at the same speed at a given time, and exit the zone once they have completed their individually assigned trip length. Although both approaches have already been used many times in various studies, challenging issues about congestion propagation between the reservoirs have received little attention in the literature. This presentation intends to shed some light on these questions, together with a short overview on these models. Case studies of reservoirs crossed by routes with different lengths will be presented.
14h45 Cyril Nguyen Van Phu, Ifsttar/Cosys/Grettia. Slides
Titre. A vehicle-to-infrastructure communication based algorithm for urban traffic control.
Résumé. We present a new algorithm for urban traffic light control with mixed traffic (communicating and non communicating vehicles) and mixed infrastructure (equipped and unequipped junctions). We call equipped junction here a junction with a traffic light signal (TLS) controlled by a road side unit (RSU). On such a junction, the RSU manifests its connectedness to equipped vehicles by broadcasting its communication address and geographical coordinates. The RSU builds a map of connected vehicles approaching and leaving the junction. The algorithm allows the RSU to select a traffic phase, based on the built map. The selected traffic phase is applied by the TLS; and both equipped and unequipped vehicles must respect it. The traffic management is in feedback on the traffic demand of communicating vehicles. We simulated the vehicular traffic as well as the communications. The two simulations are combined in a closed loop with visualization and monitoring interfaces. Several indicators on vehicular traffic (mean travel time, ended vehicles) and IEEE 802.11p communication performances (end-to-end delay, output rate, throughput, and packet error delivery ratio) are derived and illustrated in three dimension maps. We then extended the traffic control to a urban road network where we also varied the number of equipped junctions. Other indicators are shown for road traffic in the case of a road network control where high gains are experienced in the simulation results.
15h30 Pause Café.
15h45 Kwami Sossoe, Ifsttar/Cosys/Grettia. Slides
Titre. Reactive Dynamic Assignment in Discrete-continuous Large-scale Transport networks.