Safety considerations on teenage pedestrian–bus impact

Abstract

This work studies the impact conditions between the adolescent pedestrian and the bus focusing on head and chest injury. The injury to the head is analyzed using both the Head Injury Criterion (HIC) 36 and the HIC15 parameters as established by the most advanced legislation and comparing the risk probability Abbreviated Injury Scale (AIS3+) and AIS4+. The parameter HIC15 gives a higher probability of risk with lower values, and therefore it can be considered more conservative. Moreover, the study of chest injury is performed with two different biomechanical parameters: the Thoracic Trauma Index (TTI) and the TTI(d); the last neglects the pedestrian mass. The results indicate that the parameters are equivalent for the assessment of chest injury. Instead the front pedestrian collision is characterized by 3 ms criterion. The results comparison with those obtained previously with other types of vehicles shows that, in all cases, the impact with the bus is most dangerous for the teenage pedestrian because of the higher values of the biomechanical parameters. Finally, the influence of the vehicle mass has been investigated, emphasizing how it cannot be neglected a priori. Numerical analysis results are in very good agreement with the results carried out experimentally, from several authors, in real accidents where buses are involved.