Nissan collaborated in the creation of a potential next generation pedestrian alert technology which produces effective and targetable audible cues to alert pedestrians and other vulnerable road users to the presence of a nearby EV, while having minimal impact on noise pollution levels.
The sounds created were clearly audible without affecting the sound level.
The sound created not only had to be directionally beamed at targeted pedestrians, it also had to keep annoyance levels to a minimum. Siren-like noises were ruled out at an early stage, as they were found to be irritating, loud and, in some cases, emotionally upsetting to other road users.
The final version of the system features a camera built into the windscreen, which is programmed to recognize pedestrians, cyclists and other road users. On detection of a road user, six loudspeakers directionally beam sound at the target to alert them of the presence of the EV. The sound is up to five decibels lower than the sound of a conventional petrol or diesel engine vehicle.
Nissan built this system into a Nissan LEAF for real-life trials, and the vehicle was used to showcase the completed alert system at a concluding event in Barcelona in December 2014, where it was well-received by the visually-impaired community.
The research and results collated from this project form an invaluable reference material for future research into this area, and it is likely that it will be utilized to shape future EU legislation on EV pedestrian alert sounds.