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Relations between the occurrence of road accidents, traffic and rainfall conditions are valuable in setting safety objectives for traffic management, and in assessing the safety impacts of new traffic management systems, prior to their implementation. Based on traffic, road accidents and rain data collected over one year, on a French urban motorway network, a set of safety performance functions were estimated; each of them provides the accident risk per vehicle-kilometer for a certain type of accident, according to the occurrence of rain, and to the level of a traffic variable (average speed, occupancy, percentage of tailgating...). Analyses were carried out separately by lane and for two types of accidents: single-vehicle accidents and multiple-vehicle accidents.The relationships, although statistically significant, have yet to be validated by the treatment of another set of accidents.

EWGT 2015-Euro Working Group on Transportation, DELFT, PAYS-BAS, 14-/07/2015 - 16/07/2015; The purpose of this paper is to study the link between the occurrence of injury road accidents, the prevailing traffic conditions, and the occurrence of rain. This is useful for assessing, before its implementation, the safety impact of a new traffic management. Traffic conditions were extracted from a one year traffic database which covers 150 kilometres of two or three lanes urban motorways near the city of Marseille, in the south of France. 208 loop detectors provide the individual speeds, headways, arrival times and lengths of vehicles. Based on this information, thirteen aggregated traffic variables were constituted every six minutes, such as the average speed, occupancy, short time headways and a few combinations of speed, relative speed and time gaps. 292 injuries or fatal accidents occurred on the network during the same year. The French accident database provides their characteristics - location, time and type of accidents, meteorological conditions and other parameters addressing the infrastructure, the driver and the vehicle. The rain occurrence is provided, every six minutes, from a meteorological station. A set of safety performance functions were estimated, each one giving the risk of injury accident by vehicle-kilometre according to the level of one traffic variable and according to the occurrence of rain. Generally based on logistic regression models, analyses were carried out separately by lane and for two types of accidents -single vehicle accidents and crashes between vehicles. Some relations linking accidents with traffic variables are significant: the occurrence of single vehicle accidents is related to the speed on the fast lane; the occurrence of multiple vehicle accidents is related to occupancy.

International audience; This paper describes a framework for analysing the acceptability of pricing changes in the transport sector. This framework is based on Rawls' theory of justice and makes reference to economic efficiency (efficiently managing demand), spatial equity (guaranteed access), horizontal equity (the user pays principle) and vertical equity (the welfare of the most underprivileged). This analytical framework is then applied to an urban toll motorway that was opened in Lyon in 1997, in association with capacity restrictions on the parallel roads. The different types of efficiency and equity that were brought into play by this scheme are analysed and illustrated by quantitative results. We show how their negative aspects combined. This study shows that this framework can be applied to practical understanding of justice issues, and particularly for assessing the feasibility of road pricing schemes in urban areas.