In Europe, nearly 20% of all road deaths are pedestrians (Pace et al, 2012). Pedestrians have been protected only by the requirements for passive protection at the front of passenger cars and there has been little evidence to show that this measure has been effective. Autonomous Emergency Braking (AEB) systems have been clearly demonstrated to substantially reduce the incidence of car-to-car rear crashes and manufacturers have now extended the functionality to pedestrian, and in some cases pedal cyclist, collisions. If a comparable level of effectiveness is proven, then these systems will offer substantial reductions in the number of those killed and seriously injured on our roads. The research challenge described by this paper was the development of a test procedure that could be used to encourage the fitment of these systems and the development of high levels of performance in a way that could be linked to real world safety.

Thatcham Research led the AEB Group (a partnership of insurance research centres, OEMs and Tier ones) in the development of test procedures. This contributed substantially to the Harmonisation Platforms in a major collaboration with the vFSS group and the EU funded ASPECCS project. Work began with studies of realworld accident data. A cluster analysis identified the most prevalent collision scenarios and smaller samples of more detailed data were used to characterise each scenario in terms of speeds, impact points, relative positions and sight lines. Physical testing identified the characteristics required of the pedestrian test target and the performance of production and advanced prototype vehicles as well as establishing the conditions required for repeatability and reproducibility.

In Europe almost 75% of serious pedestrian crashes can be characterised by three scenarios:​ walking from the nearside of the road with open sight lines;​ running from the far side of the road;​ and walking out from behind a parked vehicle. In the vast majority of crashes the vehicle involved was travelling at 60 km/h or less. To ensure the systems worked well in the real world it was found that the test should involve adults and children, different impact points and different pedestrian speeds. The pedestrian target found to be most effective was the 4A design, and this was further tuned to optimise the radar and visual signatures to ensure consistent function across different sensor types and proving ground locations.

AEB has considerable potential to reduce the frequency and severity of vulnerable road user collisions. Robust test procedures, representative of real world collisions, have been developed and adopted by Euro NCAP for implementation in the 2016 ratings. However, VRU collisions are a problem in many areas of the world and the harmonisation of these tests and assessments in other NCAP regimes remains a priority, alongside the continuous technical development to expand the tests to include night-time performance and functionality in pedal cycle collisions.