Pedestrian Reconstruction Tools Applied to Pedestrian Accidents in Portugal Ricardo J.F. Portal*, João M.P. Dias* * IDMEC – Institute of Mechanical Engineering, IST – Technical University of Lisbon, PhD. Student of Mechanical Eng. Dep., Av. Rovisco Pais, 1049-001 Lisbon, Portugal, e-mail: ricardo.portal@dem.ist.utl.pt, jdias@dem.ist.utl.pt Abstract - Pedestrian accidents are one of the major concerns related with road accidents around the world. Portugal has one of the highest rates of pedestrian fatalities in Europe. In this paper an overview conditions were the pedestrian accidents occurred in Portugal is presented. In the last years, a project related with the pedestrian accidents has run in Portugal for the period 2004-2006 where 603 people died, 2097 have been severely injured and about 17000 slightly injured. Within this project all the pedestrian accidents in this period have been analysed providing global information about a wide range of aspects, since location, driver and pedestrian characteristics, weather and road conditions, among others. In addition, 50 in- depth accidents have been investigated and the data collected according the Pendant methodology. For this in-depth methodology detailed information about the accident has been collected, including injuries, vehicle damage, road conditions and road user’s behaviour and actions. An accident reconstruction has been carried for each case including the determination of the speeds and driver actions, and the analysis of the contributing factors for the accident. Depending of the accident complexity, different methodologies have been used to analyse these accident, from the classical analytical equations such as Simms and Woods, to the use of detailed computational pedestrian models as those included in the commercial software’s PC-Crash ® or Madymo ® . Also one of the goals of our investigation is the development of multibody models and methodologies for the reconstruction of pedestrian accidents. Some of these tools integrated in the commercial software Cosmos Motion ® are presented. The advantages of the different approaches are compared and discussed for some of the accidents investigated. With these tools the impact speed can be determined from the projection distance with analytical tools or PC-Crash ® , but more complex tools should be used to determine speed from the injuries, what is especially important for fatal accidents. The influence of the vehicle geometry and stiffness characteristics is another aspect analysed, where the influence of the vehicle stiffness has been determined using a combined multibody-finite elements approach within the software Madymo ® . NOTATION CARE European Road Accident Database SafetyNet European Road Safety Observatory ANSR Autoridade Nacional Segurança Rodoviária (Portuguese Authority for Road Safety) PARA Project “Peões, Atropelamentos e Reconstituição de Acidentes” (car-to-pedestrian accident reconstruction) Striking velocity Average coefficient of friction for pedestrian sliding on the ground Throw distance Pedestrian centre of mass’s height Acceleration Vehicle and pedestrian mass relation Distance travelled by the pedestrian during fall Distance travelled by the pedestrian during slide Impact velocity at the pedestrian rest position INTRODUCTION In 2006, according to the CARE Database [1], 42953 fatalities occurred on European road accidents (EU-27). The last accident data available, SafetyNet [2], shows that, in 2005, accidents related to pedestrians represents 17.5% in the total number of road traffic European fatalities (EU-18), Figure 1 shows the pedestrian fatalities as a percentage of total fatalities. Between 1991 and 2006, Portugal (comparing with the other European countries) achieved the best results with regard to reduce its fatalities on road accidents (81%), Figures 2 and 3. Contradicting this fact, Portugal is one of the countries where this problem is more serious, according to ANSR [3], in the year 2007, 974 (correcting for 30 days with 1.14 factor) people lost its lives in Portuguese roads and 3116 suffer 304