The influence of the infrastructure characteristics in urban road accidents occurence

Abstract

The knowledge of factors affecting accident occurrence has been a relevant research area for many decades due to enormous costs to society of road accidents. In Portugal, the developments in this area have focused mainly on inter-urban roads. Urban areas, which are characterized by high percentages of injury accidents (about 69% of the total between 2004 and 2008), require priority attention. This paper summarizes the result of a study which contributes to the improvement of road safety in urban areas, through the creation of tools that can be used in intervention methods in the planning and management of road networks. The first tool relates the creation of a geocoded database of road accident occurred in Lisbon between 2004 and 2007, which allowed the definition of digital maps, with the possibility of a wide range of consultations and crossing of information. The second tool concerns the development of models to estimate the frequency of accidents on urban networks, according to different disagregations: according to the road element: at intersections (three legs, four legs and roundabouts) and in segments; and according to the inclusion of explanatory variables related to the road environment: simplified (only with the exposure variables) and global (with all potential explanatory variables). These two tools can be used directly in the management of road infrastructure providing entities with expertise in road safety with accurate and detailed information about the factors involved in accidents in urban areas and their spatial distribution.