Lotus has decided to tackle the recently voiced concerns over hybrid vehicle safety concerns. Since the hybrid cars produce very little noise at slow speeds, there is an increased chance that the cars can catch a person by surprise. This is especially true for visually impaired pedestrians who rely heavily on audio inputs to judge what is occurring around them.
Lotus has created a working prototype, using a Toyota Prius, of an external sound systems that would make engine-type noises. The Prius was fit with a waterproof speaker next to the radiator that works only when the car is being electrically driven. The speaker will emit engine sounds with the appropriate pitch and frequency to match the speed of the car. This will enable pedestrians to judge how far and fast the approaching car is moving. When the hybrid’s gasoline engine starts up, the system stops emitting sound and restarts seamlessly when the electric motor takes back over.