IFSTTAR Institute Francais des science et Technologies des Transports

Saint-Dié-des-Vosges, France

IFSTTAR Institute Francais des science et Technologies des Transports

Saint-Dié-des-Vosges, France
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Betaille D.,IFSTTAR Institute Francais des science et Technologies des Transports | Peyret F.,IFSTTAR Institute Francais des science et Technologies des Transports | Voyer M.,ESGT Ecole Superieure des Geometres et Topographes
Journal of Navigation | Year: 2015

Urban positioning using the Global Positioning System (GPS) is challenging because of multipath. Urban canyons limit open sky visibility, and cause signal reflection and diffraction, resulting in significant satellite range measurement errors. The investigations reported here have been carried out in a French project called Inturb (an acronym derived from integrity and urban positioning). So far, the project has had two phases: first, a simple Three-Dimensional (3D) geometrical city modelling, called Urban Trench, has been developed and engineered manually from data sets collected in different cities. Positioning improvement in terms of accuracy was quantified where the model could be applied. Second, this modelling has been automated, based on the standard national BD Topo ® map database for France, with promising results. This geometrical modelling makes it possible to distinguish between line-of-sight satellite signals and those from non-line-of-sight. The latter, apparently bona fide, signals are caused by strong reflections, usually from buildings with a lot of steel and glass in their construction. A correction of the pseudo-range measurements of the latter is also computed and applied in the position estimator. Positioning accuracy is improved, whilst availability is kept at its maximum. In the study both manual and automatic 3D models are used in extensive experimental campaigns. Results are: first, the possibility to cover entirely any urban area in the country; second, the reduction of the median error in 3D by more than 50% on data collected in Nantes, Paris and Toulouse for a total duration of nearly ten hours; third, the compliance with standards used in most embedded maps and geographical information systems, including an assessment of the trade-off between the model simplicity and the positioning improvement. Copyright © 2015 The Royal Institute of Navigation.


Lepretre E.,IFSTTAR Institute Francais des science et Technologies des Transports | Chataigner S.,IFSTTAR Institute Francais des science et Technologies des Transports | Dieng L.,IFSTTAR Institute Francais des science et Technologies des Transports | Gaillet L.,IFSTTAR Institute Francais des science et Technologies des Transports | Cannard H.,Cerema Center Detudes Et Dexpertise Sur Les Risques
Engineering Structures | Year: 2016

The assessment of the structural resistance of historical metal structures involves a depth understanding of many factors, such as the properties of the constructions materials and the structural behaviour of the connection mode. Available information regarding the behaviour of historical riveted connections is quite limited and more information about the residual strain and stress state is still needed in order to allow the preservation of these existing structures. This paper deals with the assessment of stress and strain field which exist around the rivet hole due to the hot riveting process. Experimental specimens were manufactured with riveting technique used in aged metal bridges and different metallic materials for the joined plates were considered. Strain and thermal measurements were done during and after the overall riveting process. The results of the experimental investigation allowed the assessment of the residual strain state and the thermal response of the riveted joint. The experimental results were then used for validation of a 2D axisymmetric model. On the basis of the results obtained, the pre-stress state can be evaluated as well as the stress concentration areas where fatigue cracks may initiate. Thus, the provide findings constitute a supportive tool for further studies regarding the assessment and rehabilitation of historical riveted structures. © 2016 Elsevier Ltd


Fallah Shorshani M.,ParisTech National School of Bridges and Roads | Fallah Shorshani M.,IFSTTAR Institute Francais des science et Technologies des Transports | Seigneur C.,ParisTech National School of Bridges and Roads | Polo Rehn L.,French National Center for Scientific Research | And 6 more authors.
Transportation Research Part D: Transport and Environment | Year: 2015

Atmospheric pollutant dispersion near sources is typically simulated by Gaussian models because of their efficient compromise between reasonable accuracy and manageable computational time. However, the standard Gaussian dispersion formula applies downwind of a source under advective conditions with a well-defined wind direction and cannot calculate air pollutant concentrations under calm conditions with fluctuating wind direction and/or upwind of the emission source. Attempts have been made to address atmospheric dispersion under such conditions. This work evaluates the performance of standard and modified Gaussian plume models using measurements of NO2, PM10, PM2.5, five inorganic ions and seven metals conducted near a freeway in Grenoble, France, during 11-27 September 2011. The formulation for calm conditions significantly improves model performance. However, it appears that atmospheric dispersion due to vehicle-induced turbulence is still underestimated. Furthermore, model performance is poor for particulate species unless road dust resuspension by traffic is explicitly taken into account. © 2014 Elsevier Ltd.


Zaghdoud R.,Institute Superieur Of Gestion Of Tunis | Collart-Dutilleul S.,IFSTTAR Institute Francais des science et Technologies des Transports | Ghedira K.,Institute Superieur Of Gestion Of Tunis | Mesghouni K.,École Centrale Lille | Zidi K.,Institute Superieur Of Gestion Of Tunis
Proceedings - 2013 IEEE International Conference on Systems, Man, and Cybernetics, SMC 2013 | Year: 2013

The problem of assignment containers to AIVs in a container terminal is a complex problem, it is a combination of several problems; the dispatching problem, the vehicles routing problem and the scheduling problem. Each problem of these depends on some criteria; this makes the global problem as a multi-criteria problem. To solve this type of problem, the idea is to consider it like a mono-objective problem depending on each criterion separately. An aggregation function is calculated according to different criteria. The coefficient value of each criterion is proposed by an expert, these values can give the nearest Pareto front solution. The approach proposed in this work is a hybrid approach; genetic algorithm and Dijkstra algorithm. This approach is tested with different numbers of vehicles, for each problem separately, in order to have the best solution. The numeric results show the performance of our approach for the multi-objective problem. © 2013 IEEE.


Fallah Shorshani M.,IFSTTAR Institute Francais des science et Technologies des Transports | Fallah Shorshani M.,ParisTech National School of Bridges and Roads | Andre M.,IFSTTAR Institute Francais des science et Technologies des Transports | Bonhomme C.,ParisTech National School of Bridges and Roads | Seigneur C.,ParisTech National School of Bridges and Roads
Environmental Modelling and Software | Year: 2015

Modelling approaches for simulating air and stormwater pollution due to on-road vehicles are reviewed and discussed. Models for traffic, emissions, atmospheric dispersion, and stormwater contamination are studied with particular emphasis on their couplings to create a modelling chain. The models must be carefully selected according to the requirements and level of detail of the integrated modelling chain. Although a fair amount of research has been conducted to link air pollution and road traffic, many questions related to spatio-temporal scales, domains of validity, consistency among models, uncertainties of model simulation results, and interfaces between models remain open. The aim of this work is to review the current status of the relationships between traffic, emissions, air quality, and water quality models, to recommend modelling approaches and to propose some directions for improving the state of the science. The difficulties and challenges associated with model coupling are illustrated with specific examples. © 2014 Elsevier Ltd.


Fallah Shorshani M.,ParisTech National School of Bridges and Roads | Fallah Shorshani M.,IFSTTAR Institute Francais des science et Technologies des Transports | Bonhomme C.,ParisTech National School of Bridges and Roads | Petrucci G.,ParisTech National School of Bridges and Roads | And 2 more authors.
Environmental Science and Pollution Research | Year: 2014

Methods for simulating air pollution due to road traffic and the associated effects on stormwater runoff quality in an urban environment are examined with particular emphasis on the integration of the various simulation models into a consistent modelling chain. To that end, the models for traffic, pollutant emissions, atmospheric dispersion and deposition, and stormwater contamination are reviewed. The present study focuses on the implementation of a modelling chain for an actual urban case study, which is the contamination of water runoff by cadmium (Cd), lead (Pb), and zinc (Zn) in the Grigny urban catchment near Paris, France. First, traffic emissions are calculated with traffic inputs using the COPERT4 methodology. Next, the atmospheric dispersion of pollutants is simulated with the Polyphemus line source model and pollutant deposition fluxes in different subcatchment areas are calculated. Finally, the SWMM water quantity and quality model is used to estimate the concentrations of pollutants in stormwater runoff. The simulation results are compared to mass flow rates and concentrations of Cd, Pb and Zn measured at the catchment outlet. The contribution of local traffic to stormwater contamination is estimated to be significant for Pb and, to a lesser extent, for Zn and Cd; however, Pb is most likely overestimated due to outdated emissions factors. The results demonstrate the importance of treating distributed traffic emissions from major roadways explicitly since the impact of these sources on concentrations in the catchment outlet is underestimated when those traffic emissions are spatially averaged over the catchment area. © 2013 Springer-Verlag Berlin Heidelberg.


Degraeve B.,University of Nimes | Granie M.-A.,IFSTTAR Institute Francais des science et Technologies des Transports | Pravossoudovitch K.,Aix - Marseille University | Lo Monaco G.,Aix - Marseille University
Transportation Research Part F: Traffic Psychology and Behaviour | Year: 2015

The aim of this study was to investigate the specific contents of the social representations (SR) associated with men and women drivers and examine the effects of the social insertions of individuals (i.e., age, sex and socio-economic status) on the content and structure of these SR. A preliminary study with 414 French participants identified thematic content associated with men and women drivers using the verbal association method. Based on these themes, 833 French participants, equally distributed by age group (from 12 to 50 years-old and over), sex and socioeconomic status (SES), were asked to answer a questionnaire on men (N = 422) or women (N = 411) drivers. The results show that each of these SR is organized around three factors: incompetence, prudence and lack of self-control for women drivers; carelessness, skills and self-control for men drivers. In-group favoritism bias can be noted in both groups as male participants, more than female ones, rated men drivers as having self-control and women drivers as lacking self-control, whereas female participants, more than male ones, perceived men drivers as careless and women drivers as prudent. Despite this phenomenon, more male respondents than female ones in all age groups seemed to believe that women are not competent at driving, whereas both sexes seem to agree that men have good driving skills. Among most age groups, three characteristics associated with men drivers (confidence, speed and pleasure of driving) and four characteristics associated with female drivers (caution, civil, compliance with rules and vigilance) emerged as central in the SR. The SR associated with men drivers appeared to be stable and shared across age groups, whereas the SR associated with women drivers appeared more mixed, heterogeneous and unstable with age. Female participants with higher SES consider women drivers as more incompetent, less prudent and more lacking self-control than female participants with lower SES. © 2015 Elsevier Ltd. All rights reserved.


Licaj I.,Ifsttar Institute francais des science et technologies des transports | Licaj I.,University of Lyon | Haddak M.,Ifsttar Institute francais des science et technologies des transports | Haddak M.,University of Lyon | And 4 more authors.
Journal of Transport Geography | Year: 2012

This paper sets out to highlight and quantify the effect of individual and contextual deprivation on both access to a car driving licence and on actual driving of a car among young licence-holders in the Rhône Département (France).The three stages by which adolescents and very young adults become autonomous with regard to driving have been subjected to multilevel analyses, using a Household Travel Survey: (i) whether young persons participate in the early driving scheme at 16-17. years of age, (ii) whether young persons of 18-24. years of age hold a driving licence, and (iii) whether young licence-holders actually drive a car.At these three stages, social inequalities can be observed. This study highlights the considerable impact socioeconomic (individual but also contextual) factors and gender have on inequalities of access to car driving. Underprivileged groups suffer from disadvantages that accumulate at each stage (driving licence and car driving). The multilevel analysis of access to the car among young persons shows that considering the effects of the geographical context improves our understanding of travel inequalities. © 2011 Elsevier Ltd.


Papadimitriou E.,National Technical University of Athens | Theofilatos A.,National Technical University of Athens | Yannis G.,National Technical University of Athens | Cestac J.,IFSTTAR Institute Francais des science et Technologies des Transports | Kraiem S.,IFSTTAR Institute Francais des science et Technologies des Transports
Accident Analysis and Prevention | Year: 2014

Riding a motorcycle under the influence of alcohol is a dangerous activity, especially considering the high vulnerability of motorcyclists. The present research investigates the factors that affect the declared frequency of drink-riding among motorcyclists in Europe and explores regional differences. Data were collected from the SARTRE-4 (Social Attitudes to Road Traffic Risk in Europe) survey, which was conducted in 19 countries. A total sample of 4483 motorcyclists was interviewed by using a face-to-face questionnaire. The data were analyzed by means of multilevel ordered logit models. The results revealed significant regional differences (between Northern, Eastern and Southern European countries) in drink-riding frequencies in Europe. In general, declared drinking and riding were positively associated with gender (males), increased exposure, underestimation of risk, friends' behaviour, past accidents and alcohol ticket experience. On the other hand, it was negatively associated with underestimation of the amount of alcohol allowed before driving, and support for more severe penalties. © 2014 Elsevier Ltd.


Papadimitriou E.,National Technical University of Athens | Lassarre S.,IFSTTAR Institute Francais des science et Technologies des Transports | Yannis G.,National Technical University of Athens
Transportation Research Part F: Traffic Psychology and Behaviour | Year: 2016

The objective of this research is the development of pedestrian crossing choice models on the basis of road, traffic and human factors. For that purpose, a field survey was carried out, in which a panel of 75 pedestrians were asked to take 8 short walking trips (each one corresponding to a different walking and crossing scenario) in the Athens city centre in Greece, allowing to record their crossing behaviour in different road and traffic conditions. The same individuals were asked to fill in a questionnaire on their travel motivations, their mobility characteristics, their risk perceptions and preferences with respect to walking and road crossing, their opinion on drivers, etc. The walking and crossing scenarios' data were used to develop mixed sequential logit models of pedestrian behaviour on the basis of road and traffic characteristics. The modelling results showed that pedestrian crossing choices are significantly affected by road type, traffic flow and traffic control. The questionnaire data were used to estimate human factors (components) of pedestrian crossing behaviour by means of principal component analysis. The results showed that three components of pedestrian crossing behaviour emerge, namely a "risk-taking and optimisation" component reflecting the tendency to cross at mid-block in order to save time, etc., a "conservative" component, concerning individuals with increased perceived risk of mid-block crossing, who also appear to be frequent public transport users, and a "pedestrian for pleasure" component, bringing together frequent pedestrians, walking for health or pleasure, etc. The introduction of these components as explanatory variables into the choice models resulted in improvement of the modelling results, indicating that human factors have additional explanatory power over road and traffic factors of pedestrian behaviour. Therefore, the development of integrated choice and latent variables models appears to be an appropriate field for further research. © 2015 Elsevier Ltd.

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