Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux

Type de document

RAPPORT DE RECHERCHE

Langue

anglais

Auteur

ANDRE ; HAMMARSTROM ; REYNAUD

Résumé / Abstract

Road traffic related data are required for estimating air pollutant emissions from transport. Data requirements involve locating and quantifying the transport activity and assigning the corresponding driving conditions, per detailed categories of vehicles. In order to identify which data was available, a questionnaire was addressed to international and national organisations. The different sources were examined as regards their ability to provide the necessary data and their pertinence. Most of the time, it is not possible to associate consistent data on the three themes: location, quantification and driving patterns. International sources provide harmonised data, easy to obtain and to manage, but at large scale. Such data should be considered at least to complete the forecast approaches that are not necessarily well set-up with the observed statistics. National surveys and specific studies are very heterogeneous in terms of methods and results, and their access is difficult. The synthesis of statistics from France, Sweden, Great-Britain, Switzerland, Germany, and from the international institutions enabled to highlight various aspects: - significant discrepancies in the statistics are observed between different international organisations, between institutions from a same country, between different methods of investigations, - a great uncertainty and a low reliability can be observed even for data that could appear as 'common' (network length, traffic volume distribution by transport modes, etc.), - difficulties are encountered to satisfy the detailed vehicle categories and to affect traffic volumes and driving conditions according to urban - rural - motorway areas, to gradient, etc. Finally a very large quantity of traffic related statistics are provided from this works: description of the road network, analysis of the traffic distribution according to geographical areas and vehicles categories, characterisation of the driving conditions and speeds. A high number of speeds statistics are proposed that highlight the impact of numerous factors, but also the necessity to validate the reference speed values used in emissions inventories. Annual mileage, trip characteristics, parking conditions are also described, as well as load factors, gradient, fuel properties and thermal operating conditions. RAPPORT DE CONTRAT

Editeur

Institut National de Recherche sur les Transports et Leur Sécurité - INRETS