Vulnerable road users, especially pedestrians, are more susceptible to fatal and serious injury compared with vehicle occupants. Although the frequency of accidents involving pedestrians has reduced in recent years, there are still approximately 800 pedestrians killed and 7,000 seriously injured every year in Great Britain. Furthermore, in the late nineties, more than 6,000 pedestrians were fatally injured annually on EU roads, accounting for approximately 20% of all road fatalities.

The kinematics of pedestrian impacts has been well documented and test procedures have been adopted by EuroNCAP and changes made to EU regulation. Whilst this is aimed at driving improved pedestrian-friendly car design, further benefits could be achieved with the use of pre-crash sensing and active safety systems. Such systems require sensors capable of accurately and reliably detecting the presence of a pedestrian prior to a collision, and activating protective countermeasures effectively in order to reduce the pedestrian injury risk.

Accident data has been collected as part of a project developing a sensing system for cars capable of detecting and reacting to the presence of pedestrians. Systems that use radar, infra-red, laser, or ultrasound sensors to scan the 'target area' for obstacles, must be intrinsically safe, accurate and reliable, yet low cost in mass-production. A sensor array comprising both radar and infra-red devices has been developed as part of a project for the UK Foresight Vehicle programme. Other work has involved systems that have been developed to demonstrate the potential for using external airbags to provide a means of protecting pedestrians during a frontal impact.

This paper examines the pedestrian accident data, and the specification and application for pre-crash sensing. Systems for pedestrian detection and protection have been developed and the research in these areas is described.