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Some ageing bridges exposed to heavy traffic loads or abnormal loads may have critical details, either against extreme loads or in fatigue. Old bridges were designed with design codes and load models which are now exceeded by the authorized vehicle loads. Therefore, keeping the bridge safety and reliability at an acceptable level requires periodical reassessments of some structural parts, using updated traffic data, e.g. weigh-in-motion (WIM) data. For extreme loads and current ultimate limit states, extrapolated maximum axle, vehicle or total loads, depending on the considered effect and influence line length, are used to assess the maximum load effects which may be exceeded with a given probability. They are compared to the design loads affected of the partial safety factors. For fatigue limit state and lifetime assessment, the updated traffic loads, if available, or some estimation based on similar traffic flow, are used to calculate expected lifetime with the Miner's law and fatigue resistance (S-N) curves. These lifetimes are compared to the required ones, taking into account the elapsed bridge lifetime. In several country, like in France, abnormal loads regulation was made more flexible in order to avoid long administrative delay to get the permits, and up to some gross vehicle weight limits, the permit can be obtained very easily and quickly on-line through Internet. Some routes are allowed to different classes (1 to 3 in France) of abnormal loads, up to 120 t. Before labelling a route for a given class, all the sensitive bridges should be checked. In 2017, the prefect of Normandy asked to open the bridge of Normandy to the class 3 abnormal loads (120 t). The bridge concessionaire and the Ministry of Transport appointed IFSTTAR and a consulting company (Quadric) to perform some assessment of the impact of these abnormal loads on the bridge orthotropic deck lifetime in fatigue. The paper will present some of the sensitive bridges and details, a quick review of abnormal loads or load models, the trend of heavy vehicle weight limits in the EU, and then the impact of these loads on existing bridges. A special focus will be done on the study carried out for the fatigue of Normandy bridge under current and abnormal traffic loads, and how the abnormal loads can reduce the bridge lifetime. These results are useful for the decision makers to take the final decision on abnormal load authorization.

The 12th International Workshop on Structural Health Monitoring : IWSHM 2019 September 10-12, 2019, Stanford, California, USA, STANFORD, ETATS-UNIS, 10-/09/2019 - 12/09/2019; Design rules in normative documents provide additional capacity to structures by using safety coefficients and considering the worst cases of loads that in most cases never occur during the life of a structure. This extra capacity allows not only to stay on a safe side during the design operational period of structures but also to re-estimate and to extend their possible operational life. One of the most appropriate ways to estimate the remaining life of an existing structure is the extrapolation of monitored actions or load effects in critical details. The main objective of the current study is the assessment of the reliability of the steel orthotropic deck of a viaduct at the end of its design life based on limited data for traffic and static wind actions. The object of study is the Millau viaduct, a cable-stayed bridge located in Southern France, which is exposed to both, heavy traffic loads and wind loading among other actions. Monitoring data used for traffic are provided from the bridge weigh-in-motion system and include six months of data for the more loaded side of the bridge. Wind velocity and directions for the same period are taken from the structural health monitoring system of the viaduct and the nearest weather station. The methodology is based on fitting the generalized Pareto distribution to extreme stresses induced by traffic actions and by wind in order to obtain return levels at the end of the 120 years design live. Reliability indexes for the most critical part of the deck are calculated for both types of load effects separately and for their combination. Moreover, the comparison between models based on data from monitoring and on European standard models is shown.

Platooning technology has made significant advances in the last decade, but to achieve the next step towards deployment of truck platooning, an integral multi-brand approach is required. It is the ambition of ENSEMBLE to realize pre-standards for interoperability between trucks, platoons and logistics solution providers, to speed up actual market pick-up of (sub)system development and implementation, and to enable harmonization of legal frameworks in the member states. This paper provides with definition of the specifications of the whole multi-brand truck platooning concept to be implemented within the testing and demonstration trucks of the 6 OEMs. It describes the functional architecture, captures all minimum set of operations layer requirements and tactical layer specifications for Platoon level A. The building blocks of truck platooning consist of in-vehicle requirements (Longitudinal, sensors, HMI interaction), infrastructure (V2I), information among trucks in platoon, and platooning strategy (coordination mode, gap regulation, formation, dissolution, and vehicle mix)., La technologie de peloton a fait des progrès significatifs au cours de la dernière décennie, mais pour franchir la prochaine étape du déploiement de pelotons de camions, une approche multimarques intégrée est indispensable. Le projet ENSEMBLE a pour ambition de mettre en place des pré-normes en matière d'interopérabilité entre les camions, les pelotons et les fournisseurs de solutions logistiques, d'accélérer le développement et la mise en oeuvre de (sous-) systèmes sur le marché et de permettre l'harmonisation des cadres juridiques dans les États membres européens. Ce document fournit une définition des spécifications du concept de groupement de camions multimarques à mettre en oeuvre dans les camions de test et de démonstration des 6 constructeurs. Il décrit l'architecture fonctionnelle, capture l'ensemble des exigences minimales de la couche d'exploitation et des spécifications de la couche tactique pour le niveau A. Les éléments constitutifs du groupement de camions sont les exigences embarquées (longitudinal, capteurs, interaction IHM), infrastructure (V2I), informations entre camions du peloton et stratégie de peloton (mode de coordination, régulation des écarts, formation, dissolution et combinaison de véhicules).

The local authorities asked in 2017 the concessionaire of the bridge of Normandy (CCISE), a 856 span length cable stayed bridge, to study the feasibility opening it to abnormal loads up to 120 t. The CCISE asked the advice of the bridge designer, M. Virlogeux, and to IFSTTAR, to measure the current traffic loads on the bridge, in operation since 1994, to assess the fatigue lifetime under this real traffic loads, and to estimate the potential lifetime reduction if the abnormal loads up to 120 t were allowed. IFSTTAR and Cerema installed a bridge WIM system (SiWIM) in July 2017 on the bridge to measure the traffic loads over more than 7 months. These data allowed assessing the expected lifetimes of the most sensitive details of the orthotropic steel deck. These lifetimes were compared with those obtained under 3 other traffics recorded on other French motorways. Then the fatigue damage induced by 4 conventional abnormal loads (2 cranes of 96 and 108 t, and to vehicles C1 and C2 of 94 and 120 t) was calculated. Finally, the lifetime reduction if each of these 4 abnormal loads cross the bridge twice a day was assessed., Les autorités locales ont demandé en 2017 au concessionnaire du pont de Normandie (CCISE), ouvrage haubané de 856 m de portée, d'étudier la possibilité d'ouvrir le pont à des transports exceptionnels jusqu'à 120 t. La CCISE a demandé l'avis du concepteur de l'ouvrage, M. Virlogeux, et à l'IFSTTAR de mesurer les charges de trafic sur le pont en service depuis 1994, d'estimer la durée de vie en fatigue et sa réduction potentielle si les convois jusqu'à 120 t étaient autorisés. L'IFSTTAR et le Cerema ont installé un système de pesage par pont instrumenté (SiWIM) en juillet 2017 pour mesurer les charges de trafic pendant plus de 7 mois. Ces données ont permis de calculer les durées de vie des détails les plus sensibles du platelage de la dalle orthotrope. Ces durées de vie ont été comparées à celles obtenues avec 3 autres trafics autoroutiers français. Ensuite le dommage en fatigue induit par 4 convois exceptionnels (2 grues de 96 et 108 t et 2 convois conventionnels C1 et C2 de 94 et 120 t) a été calculé. Finalement la réduction de durée de vie du pont a été estimée si chacun de ces 4 convois passaient 2 fois par jour.

ICWIM8, 8th International Conference on Weigh-in-Motion, PRAGUE, TCHÈQUE, RÉPUBLIQUE, 20-/05/2019 - 24/05/2019; The conference addresses the broad range of topics related to on-road and in-vehicle WIM technology, its research, installation and operation and use of mass data across variable end-uses. Innovative technologies and experiences of WIM system implementation are presented. Application of WIM data to infrastructure, mainly bridges and pavements, is among the main topics. However, the most demanding application is now WIM for enforcement, and the greatest challenge is WIM for direct enforcement. Most of the countries and road authorities should ensure a full compliance of heavy vehicle weights and dimensions with the current regulations. Another challenging objective is to extend the lifetimes of existing road assets, despite of increasing heavy vehicle loads and flow, and without compromising with the structural safety. Fair competition and road charging also require accurately monitoring commercial vehicle weights by WIM. WIM contributes to a global ITS (Intelligent Transport System) providing useful data on heavy good vehicles to implement Performance Based Standards (PBS) and Intelligent Access Programme (IAP, Australia) or Smart Infrastructure Access Programme (SIAP). The conference reports the latest research and developments since the last conference in 2016, from all around the World. More than 150 delegates from 33 countries and all continents are attending ICWIM8, mixing academics, end users, decision makers and WIM vendors. An industrial exhibition is organized jointly with the conference.

TRB, Transportation Research Board Annual Meeting, WASHINGTON, ETATS-UNIS, 13-/01/2019 - 17/01/2019; Due to a request to open the Normandy bridge in France to abnormal loads, some detailed investigations have been carried out on the current traffic loads, and on the expected fatigue lifetimes, with and without the abnormal loads. This long span cable-stayed bridge is made of a steel orthotropic deck, quite sensitive to fatigue under traffic loads. Using the simplest standardized fatigue load model of the Eurocodes (LM3 of Eurocode 1991-2) is much too conservative and leads to unrealistic calculated lifetimes of a few years. Therefore, a real traffic load assessment was performed with a Weigh-in-Motion (WIM) system. A bridge WIM (B-WIM) system has been installed on the bridge, and the traffic loads were measured continuously over 7 months. The influence lines of the most sensitive details, mainly at the welds between deck plate and longitudinal stiffeners, at various transversal locations, were re-calculated with a 3-D finite element model (FEM), and compared to former measured influence lines. Fatigue lifetimes were assessed using the Miner's law, using successively a simplified load model made of a standard tridem axle, the measured traffic loads on the Normandy bridge, some measured traffic loads on other French motorways, and finally with a superimposition of the current traffic loads and the expected abnormal loads. The transverse location of the wheels on the deck has a great influence on the fatigue damage. With all these results, pratical recommendations were delivered to the bridge concessionary about the acceptability of the abnormal loads.

ICWIM7 - 7th International Conference on Weigh-In-Motion, FOZ DO IGUACU, BRESIL, 07-/11/2016 - 10/11/2016; WIM data makes it possible to assess precisely the consequences of changes in the regulations on the weight and dimensions of the trucks in the impact on infrastructures. This is the case for impact on pavement (changes in the fatigue and rutting), on the compliance with geometrical constraints (geometry of the road and ability to drive on the existing infrastructure) and on bridge loading. We intend to present in this paper several studies on bridge loading based on WIM data and that have been conducted recently in France. In a first study, the impact of the increase of the limit of 40t for GVW for 5 axle-trucks to 44t has been investigated. It has been shown that a decrease in lifetime of the structures should be expected (decrease by approximately 10%). Another study has studied the effect of the changes in traffic between 1989 (when the European design codes for bridges have been written) and 2010. These changes have been shown with use of WIM data from 1989 and 2010: the traffic recorded in 2010 has effects beneath those induced by Load Model 1 of Eurocode 1 for bridges with spans higher than 20m, but the safety margin is reduced.

ICWIM7 - 7th International Conference on Weigh-In-Motion, FOZ DO IGUACU, BRESIL, 07-/11/2016 - 10/11/2016; Heavy commercial vehicle overloads contribute to deterioration of infrastructure and increase road unsafety and unfair competition between transport modes and operators. An efficient enforcement system of weights and dimensions at an affordable cost is therefore required. A large scale project was launched by the French Ministry of Transport in 2014 in France, led by IFSTTAR, in cooperation with the Cerema, to demonstrate the feasibility of using high speed weigh-in-motion (HS-WIM) systems for direct enforcement of overloads. This ambitious challenge requires overcoming technological and metrological gaps, and modifying the current legislation. The required tolerances are ±5% for the gross vehicle weight, and ±10% for axle loads for 100% of the vehicles. The methodology is to develop sorting criteria and algorithms, eliminating the outliers, that is to say the weighing data outside these tolerances. The project organization and management is described and the first results are presented in this paper.

ATEC ITS France, Montrouge, FRANCE, 26-/01/2016 - 27/01/2016; La connaissance et le contrôle des poids et dimensions des poids lourds du trafic est nécessaire pour les autorités publiques et les gestionnaires d'infrastructures, tant pour des raisons de gestion de ces infrastructures que de contrôle du respect des limitations imposées. Le pesage en marche des Îhicules permet de répondre à cette problématique. L'utilisation de celui-ci est d'ailleurs une obligation mise en place par la nouvelle version de la Directive 96/53/EC. Il utilise traditionnellement des capteurs en chaussée qui comptent, mesurent et pèsent les Îhicules les franchissant. Cette solution est actuellement utilisée en France par le réseau national des équipements de pesage en marche (EPM). Néanmoins une autre solution existe, le pesage par pont instrumenté, qui consiste à mesurer les déformations d'un pont au passage des poids lourds du trafic et en déduire leurs poids et dimensions. Le principe introduit à la fin des années 1970 a été amélioré dans le projet européen WAVE (1996-98). Le pesage par ponts instrumentés est à présent mature, et utilisable pour les mêmes applications qu'avec des capteurs en chaussée. Néanmoins, le pesage à vitesse courante n'est actuellement pas certifié par la métrologie légale, et ne peut être utilisé pour le contrôle sanction des surcharges. Nous présentons ici les résultats obtenus lors d'essais réalisés sur un pont cadre du réseau SANEF sur l'autoroute A1 près de Senlis. Les différences entre pesées statiques de référence et par le pont instrumenté sont traitées à l'aide de la pré-norme COST323 pour établir la classe de précision du système. Elles sont également analysées vis-à-vis de critères physiques pour rechercher des pistes d'amélioration. Des exemples d'application de ce système sont présentés.

ICWIM7 - 7th International Conference on Weigh-In-Motion, FOZ DO IGUACU, BRESIL, 07-/11/2016 - 10/11/2016; Actes de la conférence ICWIM7

TRA2014 Transport Research Arena 2014 Transport Solutions : from Research to Deployment - Innovate Mobility, Mobilise Innovation, PARIS-LA DEFENSE, FRANCE, 14-/04/2014 - 17/04/2014; This book is part of a set of six books called the 'Research for Innovative Transports' set. This collection presents an update of the latest academic and applied research, case studies, best practices and user perspectives on transport carried out in Europe and worldwide. The volumes are made up of a selection of the best papers presented at TRA2014. This book provides an overview of the latest technological innovations in Europe and worldwide, based on ICT and new vehicle concepts, for all modes and all scales (urban, regional, national or international). The authors consider innovation supply, the process of innovation and innovative business models. Some perspectives and solutions are proposed on the deployment of innovation, specifically concerning the transformation of the organization of the system and the relationships between industry, governmental players, operators and users.

Context and objectives, Truck classification, Wim data, Axle load distribution, load patterns, Methodology.

25ème Congrès de l'AIPCR, SEOUL, COREE, REPUBLIQUE DE, 02-/11/2015 - 05/11/2015; The knowledge of heavy vehicle traffic on the road network plays a key role for transport policy and road operators to : - increase the mobility by adapting the policies,- improve road safety, - reduce unfair competition between transport modes and companies, - optimise infrastructure lifetime, and thus to ensure weights and dimensions compliance and to enforce the traffic regulations. Since 2008, 29 WIM systems were installed for the French Ministry of Transport on the main road network, i.e. highways and motorways. They continuously screen overloaded and speeding vehicles and allow to target the controls on presumed violators. The check efficiency was increased by a factor 3, and the accuracy of the WIM systems now allows envisioning the future development of an automated overload control (AOC) system. These systems also allow profiling companies which are frequently infringing the driving law and to target the checks in companies. Detailed heavy traffic data are gathered on a large scale, both as classified flows (statistics), and individual data per vehicle. These data are stored in a National database, and used for statistics, for infrastructure design and management, and for traffic monitoring. Examples of application to pavement and bridge assessment are presented.

25 ème congrès de l'AIPCR, SEOUL, COREE, REPUBLIQUE DE, 02-/11/2015 - 05/11/2015; Heavy vehicle overloads contribute to premature deterioration of infrastructure and increase road unsafety and unfair competition between transport modes and operators. Public authorities and road operators must therefore implement an efficient checking system to enforce weights and dimensions at an affordable cost. WIM technologies are widely used for screening overloaded vehicles, and sometime to issue warnings to the violators. However, these systems are mostly not yet approved by the Legal Metrology for automated overload control and fining. With the traffic volume increase, the safety constraints and the downsizing of traffic officer staff, it becomes necessary to introduce automated overload control by WIM. The ongoing Automated Overloads Control (AOC) project, supported by the French Ministry of Transports (DGITM) and carried out by IFSTTAR and CEREMA, aims to demonstrate the feasibility of automated overload enforcement with adapted existing WIM technologies to be certified. The project is carried out in partnership with WIM vendors. Trials have been carried out in lab and on the large pavement testing facility of IFSTTAR in Nantes. Sorting algorithms will be developed to identify the vehicles weighed within the required tolerances and on road trials are planned to demonstrate the feasibility of the whole system.

Bridge weigh-in-motion uses an instrumented bridge as a scale to weigh vehicles. Several types of bridges may be used, if being sensitive to wheel or axle loads. Here some strains of steel orthotropic deck bridges are measured by extensometers and analyzed by software, to calculate axle loads and gross vehicle weights. Between 2009 and 2011, several large scale tests were done on the Millau viaduct (France), the tallest cable stayed bridge in the world. These tests showed that the system meets the accuracy class C(15)/D+(20) of the European WIM Specifications. The data obtained can be used for fatigue checks, because it assesses truck sizes and weights of the traffic and the behaviour of the bridge. We show here that bridge lifetimes under current and possible future traffic loads, after an increase of the GVW limit from 40 tons to 44 tons in France, could be reduced by 20%.

WIM systems are still a fairly young technology. Like many developing technology platforms, these are subject to fragmentation in terms of uses and standards. This paper addresses to efforts aimed at dealing with this fragmentation by observing two on-going projects. First system considered is the FIWI WIM database led by ISWIM, which through a cooperative effort aims at creating a WIM sensors and systems cartography. Second system considered is SITL system, which aims at developing a WIM data processing system. It is based mostly on open-source or free-use software. This system, while having a short term operational goals, is also meant as a demonstrator for promoting a formal WIM data model. Those two projects aim at serving and strengthing WIM users community by mutual understanding and promotion of common tools.

Bridge-Weigh-In-Motion uses bridges as a scale to weigh vehicles. Practically, this is done by measuring the strains in that bridge, and relating them to the weight and dimensions of a truck called “calibration trucks” whose shape and axle weights are well known. This article summarizes different B-WIM experiments the institute IFSTTAR (formerly called LCPC) realized and the lessons drawn from this experience. First, the system has been tested on frame-type bridges with integral slab decks. Different parameters have been investigated like the quality of the surface of the pavement and the transversal shape of the road. Since, orthotropic plate bridges have been instrumented. Several points need to be further improved. B-WIM, Free of Axle Detectors

With more than 75% of freight in most EU countries, road traffic is the most dominant mode for the transport of goods. The proportion of heavy duty vehicles (HDV) increases in traffic and often reaches 15 to 20%. To achieve the new objectives of sustainable development, ensuring the sustainability of infrastructure and improving road safety, a special attention should be paid to this mode of transportation to assess and reduce the dynamic loads of the wheels and axles on pavements. The safety and efficiency of HDV can be improved by the use of on-board systems for the monitoring and the estimation of dynamic loads in real time. The progress in development of new tools in control theory provides interesting techniques for the weigh-in-motion board. The objective of this thesis is to develop a method to estimate the impact forces of heavy vehicles on the roadways and to provide an active control to reduce the maximum dynamic effects. After a detailed state of art about available on-board weighing technology, a yaw-roll model dynamics of the HDV is developed. Estimation methods based on explicit and implicit model inversion and sliding mode observers are developed and tested using the Prosper/Callas simulator and a first validation is obtained by experimental tests. Finally, control architecture for active steering, based on the estimated impact forces in order to alert and assist the driver in the presence of rollover risk and dangerous situations is proposed.; Avec plus de 75% du fret dans la plupart des pays de l’UE, le mode routier reste le plus dominant pour le transport de marchandises. La proportion de Poids Lourds (PL) croît dans le trafic routier et atteint souvent 15 à 20%. Pour atteindre les nouveaux objectifs de développement durable, garantir la durabilité des infrastructures et améliorer la sécurité routière, une attention particulière doit être portée sur ce mode de transport pour évaluer et limiter les charges dynamiques des roues et essieux sur les chaussées. La sécurité et l’efficacité des PL peuvent être améliorées par l’utilisation de systèmes embarqués permettant la surveillance continue et l’estimation des charges dynamiques en temps réel. Les progrès des outils de l’automatique fournissent des techniques intéressantes pour le pesage en marche embarqué. L’objectif de cette thèse est de développer une méthode d’estimation des forces d’impacts des poids lourds sur les chaussées et de proposer un contrôle actif pour réduire les effets dynamiques maximaux. Après un état de l’art détaillé sur les techniques de pesage embarqué disponibles, un modèle lacet-roulis dynamique du PL est développé. Des méthodes d’estimations basées sur l’inversion explicite et implicite du modèle et d’observateurs à mode glissant sont développées et testés à l’aide du simulateur Prosper/Callas et une première validation a été obtenue par des tests expérimentaux. Enfin, une architecture de commande par braquage actif, basée sur les forces d’impact estimées et permettant d’alerter et d’assister le conducteur en présence de risque de renversement et de situations accidentogènes a été proposée.

In this paper, we are interested in developing a robust tire-force estimator for heavy duty vehicles. We use a combined model of the articulated vehicle: a yaw plane model for the chassis motion and a vertical plane model for the axles. In the proposed method, we make use of the on-board available sensors to which are added low-cost sensors. In order to optimize the sensors configuration, a robust differentiator is used in order to obtain accelerations from the measured velocities. Once the differentiation obtained, the model is inverted to determine the unknown input forces. The approach is validated by comparing the estimation results to those given by the software simulator prosper.

Bridge code calibration and assessment of existing bridges require an accurate knowledge of traffic load patterns. WIM data are useful for these applications, either to account for the current traffic loads or to assess the potential impact of future loads. Traffic load effects were calculated on two composite bridges, using WIM data of a French motorway, and the effect of an increase of the gross weight limit from 40 to 44 tons was assessed by a micro-simulation. Extreme values and fatigue lifetimes are calculated and compared for the current traffic and a traffic with the increased weight limit. The lifetime of details sensitive in fatigue could be decreased by 20% if the weight regulation is changed.

Le mode routier est dominant pour le transport de marchandises, avec plus de 75% du fret dans la plupart des pays de l'Union européenne. En outre, la proportion de poids lourds croît dans le trafic routier et atteint souvent 15 à 20%. Par conséquent, pour atteindre les nouveaux objectifs de développement durable et pour les infrastructures, une attention particulière doit être portée pour évaluer et limiter les charges dynamiques des roues et essieux sur les chaussées, pour garantir leur durabilité. La sécurité et l'efficacité des poids lourds peuvent être améliorées par une surveillance continue embarquée des charges de roues, servant à des systèmes anti-renversement ou de stabilisation. Les progrès de la théorie du contrôle fournissent des techniques intéressantes pour le pesage en marche embarqué. L'idée est de développer des systèmes intelligents d'estimation des forces d'impacts des poids lourds sur les chaussées et un contrôle actif pour réduire les effets dynamiques maximaux.

La part de la route dans le transport de marchandises est largement prépondérante en France et en Europe (75% du tonnage transporté). Le trafic des poids lourds est en forte augmentation ces dernières années (+12,1% en 5 ans), et on constate un accroissement inquiétant de la fréquence des surcharges, générant une distorsion de la concurrence, un accroissement de l'insécurité routière et la détérioration potentielle des infrastructures. Le chapitre 1 présente des résultats sur l'accidentologie des poids lourds dans différentes études récentes. Le chapitre 2 montre les relations entre ces accidents et les caractéristiques de l'infrastructure et propose des seuils de sécurité (vitesse, rayon de courbure, dévers, l'adhérence et pente), à partir de simulations. Le chapitre 3 traite de la route automatisée poids lourds comme un moyen potentiel d'accroître la capacité des infrastructures. Le chapitre 4 présente un modèle dynamique original de poids lourd permettant de prédire le renversement d'un poids lourd et de fournir des alertes au chauffeur. Le chapitre 5 donne les résultats obtenus sur les systèmes de pesage en marche - à basse vitesse et sous trafic - par multicapteurs et par ponts instrumentés. Des perspectives de recherche complémentaires sont proposées dans le domaine du transport routier de marchandises.

The conference addresses the broad range of technical issues related to heavy vehicles, surface transport technology, safety and weight measurement systems. It provides access to current research, best practice and related policy issues. It is a multi-disciplinary, inter-agency supported event.

Sommaire : Heavy vehicles and WIM technology, testing and standards. Interactions between heavy vehicles or trains and the infrastructure, environment and other system users. Heavy vehicle and road management information: measurements, data quality, data management. Freight mobility and safety. Vehicle classification, size and weight evaluation, regulations and enforcement. Traffic and road safety. WIM of road vehicles, trains and aeroplanes.

Compte tenu des progrès techniques réalisés ces dernières années, il paraît opportun de se poser globalement la question des possibilités optimales d'exploitation des nouvelles technologies d'échanges d'information et de la métrologie du trafic pour les véhicules poids lourds de transport routier de marchandises. L'objectif du travail proposé est de développer un système interactif : Poids lourd/Infrastructure/Centre de contrôle permettant d'évaluer les conditions d'accès du poids lourd à l'infrastructure, en fonction de sa charge, les infos trafic et les conditions météorologiques. L'autorisation ou l'interdiction de l'accès du poids lourd est alors décidée. Des techniques de communications sont utilisées pour assurer la communication entre ces trois entités pour échanger des informations.

This paper presents a study carried out with extensive weigh-in-motion (WIM) data collected on the French main road network, involving 3 millions of trucks. The data were collected by three WIM stations located on highly trafficked highways and motorways, continuously over a whole year. The data were analyzed using statistical software developed by the US National Science Foundation. The trucks of the traffic flow were classified into almost 20 categories, depending on the silhouette, number and spacing of axles, body configuration (trailer/semi-trailer), type of axles (steering, driving or standard axle) and wheel or tire (single, twin, wide). The data were analyzed by category. The location of the centre of gravity of the payload was calculated and the variability of its abscissa along the vehicle was analyzed in each category. The loading patterns and behavior were analyzed and the results reported here for 5-axle articulated trucks and 2-axle rigid truck with 2-axle trailer. Then, the axle load distributions were analyzed by axle rank and truck category, and modeled with multimodal Gaussian probability distribution functions. The modes have been determined using a maximum of likelihood method. These modes are useful to design endurance tests of truck tires. These investigations provide a better knowledge about truck loading, overloads and truck aggressiveness on infrastructure, and may lead to optimization policies. In this case, the results are used directly in the domain of tyre optimization.