Abstract

TRB 2014 - Transportation Research Board 93rd Annual Meeting, WASHINGTON D.C, ETATS-UNIS, 12-/01/2014 - 16/01/2014; An empirical analysis is conducted on lane changing behavior using a trajectory data set collected at a weaving section in Grenoble (France). A detailed literature review shows that strong empirical understanding of the weaving mechanisms is still lacking. The goal is to investigate the lane changing behavior at a microscopic level. Data collection distinguished lane changes from the main road and those towards the main road. Descriptive empirical analysis examines the positions of the lane changes and the corresponding accepted gaps. Results show that under heavy congested traffic conditions the weaving vehicles tend to change lane as soon as possible after the start of the weaving section. When the traffic conditions are fluid, the weaving vehicles coming from the main road tend to change lane earlier than the weaving vehicles coming from the auxiliary lane. Moreover, weaving vehicles coming from the auxiliary lane accept smaller gaps and headways than the weaving vehicles coming from the main road. Our findings are questioning some results of previous works using micro-simulation to study weaving sections. As the weaving vehicles change lane at the beginning of the studied weaving section, our findings ask whether the length of the weaving section is a key variable to estimate its capacity. Our findings raise also some questions about the relevance of the gap acceptance theory to model lane changes at weaving sections. But further research are needed to asses these hypothesis.

Abstract

TRA 2018 - 7th Transport Research Arena : A digital era for transport, Vienne, AUTRICHE, 16-/04/2018 - 19/04/2018; Lane splitting is a common riding practice although forbidden by the traffic rules in France. Since February 1st, 2016, a secure shape of traffic, respectful of certain rules is allowed on motorways and urban expressways in several French departments. The objective here is to present the results concerning the acceptability of this secure form of lane splitting for motorcyclists and car drivers. 908 car drivers and motorcyclists, representative samples of the French population (in terms of sex, age and socio-professional category) were interviewed. 751 lived in the experimental area and 157, in the control area where lane splitting is not allowed. The results show that the car drivers and the motorcyclists evaluate positively the experiment, the attitude of the experiment is even more positive for the motorcyclists. But, the car drivers have some reservations about the difficulty to understand where lane splitting is allowed. The results are discussed. As we will be replicating this research in 2017 and 2018, in order to study changes in how the experiment is accepted in the long term, at the end we will have some helpful elements, to decide if LS could be allowed in France.; La circulation inter-files est une pratique courante bien qu'interdite par les règles de circulation en France. Depuis le 1er février, 2016, un trafic sécurisé, respectueux de certaines règles est autorisé expérimentalement sur les autoroutes et autoroutes urbaines dans plusieurs départements français. L'objectif ici est de présenter les résultats concernant l'acceptabilité de cette forme sécurisée de la circulation inter-files chez les motocyclistes et les automobilistes. 908 automobilistes et motocyclistes, constituant un échantillon représentatif de la population française (en termes de sexe, d'âge et catégorie socioprofessionnelle), ont été interviewés. 751 résidaient dans la zone expérimentale et 157 dans la zone de contrôle où la circulation inter-files n'est pas autorisée. Les résultats montrent que les automobilistes et les motocyclistes évaluent positivement l'expérimentation, avec une attitude encore plus positive chez les motocyclistes. Les automobilistes expriment des réserves liées la difficulté à identifier les zones où la circulation inter-files est autorisée. Cette étude sera répliquée en 2017 et 2018 afin d'étudier les changements dans la façon dont l'expérimentation est acceptée à long terme. Document type: Conference object

Abstract

Increasing mobility and congestion results in an increase in travel time variability and in a decrease in reliability. Reliability becomes an important performance measure for transportation facilities. A variety of performance measures have been proposed to quantify it. Many of these indicators are based on percentiles of travel time. The knowledge of the distribution of travel time is needed to properly estimate these values. Congestion distorts the distribution and particular statistical distributions are needed. Different distributions have been proposed in the literature. In a previous paper, we presented a comparison of six statistical distributions used to model travel time. These six distributions are the Lognormal, Gamma, Burr (extended by Singh-Maddala), Weibull, a mixture of two Normal distributions and a mixture of two Gamma distributions. In this paper a probabilistic modeling of travel time which takes into account the levels-of-service is given. Levels of service are identified, then travel time distributions are modeled by level of service. This results in a very good fit between the empirical and modeled distributions Moreover, the adjustment was improved, thanks to the calibration of “Bureau of Public Roads” functions, linking the travel time to the traffic flow by level of service. The superiority of the Singh-Maddala distribution appears in many cases. This has been validated, thanks to travel time data from the same site at another period. However the parameters of the distributions vary from one year to another, due to changes in infrastructure. The transferability of the approach, not performed, will be based on travel time data on another site. Document type: Conference object