Volvo's e-buses, which are already shuttling passengers in some European cities, are silent operators like other electric vehicles out there. The automaker's idea of minimizing their chances of colliding with pedestrians, however, is giving them the capability to make a lot of noise. Volvo's new pedestrian and cyclist detection system uses a camera to constantly monitor its buses' surroundings. If it spots someone nearby, it emits a gentle warning sound to signify that a vehicle is approaching. It also uses audio and visual cues to alert the driver of people nearby, just in case he's fallen asleep at the wheel. If it senses an "imminent risk of an accident," though, it does more than just give off a few beeps: it honks. Loudly.