Because Nissan LEAF does not have an internalcombustionengine, Nissan has incorporated an "Approaching Vehicle Sound for Pedestrians" system, which is designed to alert pedestrians that a vehicle is approaching.
The parallel full hybrid system developed by Porsche also offers "coasting" at higher speeds, a mode wherein the internalcombustionengine is turned off and the electric motors use vehicle momentum to generate electricity that is stored in the lithium-ion battery.
Everybody wants to talk about what kind of alternative vehicle we'll be driving next, but I've got news for you: The internalcombustion gasoline engine isn't going anywhere.
Because hybrid and electric vehicles produce less sound than vehicles powered by an ordinary internalcombustionengine, pedestrians may not be aware of the presence of a nearby hybrid or electric vehicle.