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Over the last years, distracted driving possesses a leading position among accident causes and it constitutes an increasing road safety problem with disastrous results. Considering external factors of distraction as highly significant, they can be grouped in four categories: built roadway, situational entities, natural environment, and built environment. The fourth category, related to civil infrastructure and commercial land use, combined with high vehicle speeds that occur in motorways, might contribute to the creation of a very dangerous environment, increasing driver distraction and inattention. Through accurate research, solid results can emerge and traffic safety can be enhanced. The present study deals with driver distraction caused by out-of-the-vehicle factors, as well as factors related to the driver, such as age, gender, driving experience etc. It covers the distraction of driver attention during driving due to external factors that are not related to the main task of driving, resulting in impairments to driver attention and decision-making ability and hence the driver’s overall performance. For this purpose, we assess the side effects of numerous road elements, such as information signs, roadside advertising, Variable Message Signs, toll buildings, noise barriers/panels etc. to driver attention. The study is based on a medium-scale experimental procedure which took place in Attica Tollway, the Ring Road of the Athens metropolitan area, which was part of a larger research project conducted by the University of Thessaly, Department of Civil Engineering that included a total of three urban freeways in Greece. In order to create the appropriate research basis and to use as reliable data as possible, the gaze tracker FaceLab software was used on a sample of 29 drivers. Each participant drove 51 km on Attica Tollway, both in level terrain with 3 lanes and speed limit up to 120 km/h and in rolling terrain with 2 lanes and speed limit up to 80 km/h. The distraction of driver attention is evaluated via a continuous recording of his/her gaze, which acts as the main indicator regarding driver performance. The results of this procedure, analyzed via Captive software, are focused on the time that the driver’s gaze remained on each of the road elements under research. The analysis offers conclusions on different aspects - driver, road element and the road in total - comparing and categorizing the results by using a 4-level timescale from 0 to 2 seconds. This study can be used as a tool that can help in understanding and limiting the use of roadside elements that are not related to the execution of the driving task, but that may serve as potential causes of distraction. The results of this type of research procedures are very useful in preventing the forthcoming pressure for more billboards and trademarks on the roads, as well as in encouraging the adaptation of more precise regulations relating to the road infrastructure, the placement of roadside elements, etc.

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.