Time-to-collision analysis of pedestrian and pedal-cycle accidents for the development of autonomous emergency braking systems

The aim of this study was to describe the position of pedestrians and pedal cyclists relative to the striking vehicle in the three seconds before impact. This information is essential for the development of e ective autonomous emergency braking systems and relevant test conditions for consumer ratings. The UK RAIDS-OTS study provided 175 pedestrian and 127 pedal-cycle cases based on in-depth, at-scene investigations of a representative sample of accidents in 2000–2010. Pedal cyclists were scattered laterally more widely than pedestrians (90% of cyclists within around 80 degrees compared to 20 degrees for pedestrians), however their distance from the striking vehicle in the seconds before impact was no greater (90% of cyclists within 42 metres at three seconds compared to 50 metres for pedestrians). This data is consistent with a greater involvement of slow moving vehicles in cycle accidents. The implication of the results is that AEB systems for cyclists require almost complete 180 degree side-to-side vision but do not need a longer distance range than for pedestrians.