Integrated assessment of pedestrian head impact protection in testing secondary safety and autonomous emergency braking

• Published in: Accident analysis and prevention 2014-02, Vol.63, p.1-8
• Main Authors: Searson, D.J., Anderson, R.W.G., Hutchinson, T.P.
• Format: Article
• Language: English
• Subjects: Accidents, Traffic; Assessments; Automobiles; Autonomous; Autonomous emergency braking; Biological and medical sciences; Braking; Craniocerebral Trauma - prevention & control; Crashes; Deceleration; Emergencies; Equipment Design; Head impact protection; Humans; Impact testing; Injuries; Integrated assessment; Manikins; Medical sciences; Miscellaneous; Pedestrian; Pedestrians; Prevention and actions; Public health. Hygiene; Public health. Hygiene-occupational medicine; Risk; Safety; Trauma Severity Indices
• ISSN: 0001-4575; 1879-2057
• DOI: 10.1016/j.aap.2013.10.014

•We propose a method for integrating the assessment of autonomous emergency braking and secondary safety performance in respect of pedestrian head impact protections.•The basis of the method is the joint effect of impact speeds and impact test performance on average risks of head injury in pedestrian crashes.•Effective AEB when combined with good secondary safety performance is likely to radically reduce average risks.•The results suggest straightforward ways in which to integrate varying levels of AEB performance into Euro NCAP-style pedestrian ratings. Pedestrian impact testing is used to provide information to the public about the relative level of protection provided by different vehicles to a struck pedestrian. Autonomous Emergency Braking (AEB) is a relatively new technology that aims to reduce the impact speed of such crashes. It is expected that vehicles with AEB will pose less harm to pedestrians, and that the benefit will come about through reductions in the number of collisions and a change in the severity of impacts that will still occur. In this paper, an integration of the assessment of AEB performance and impact performance is proposed based on average injury risk. Average injury risk is calculated using the result of an impact test and a previously published distribution of real world crash speeds. A second published speed distribution is used that accounts for the effects of AEB, and reduced average risks are implied. This principle allows the effects of AEB systems and secondary safety performance to be integrated into a single measure of safety. The results are used to examine the effect of AEB on Euro NCAP and ANCAP assessments using previously published results on the likely effect of AEB. The results show that, given certain assumptions about AEB performance, the addition of AEB is approximately the equivalent of increasing Euro NCAP test performance by one band, which corresponds to an increase in the score of 25% of the maximum.