A blind friend of mine could not hear a car approaching as it was electric. Luckily her guide dog would not allow her to cross, even though she urged him on as she 'thought' the road was clear. I have also witnessed a relative of mine almost hit by an electric car in a car park as there was no sound to indicate it was reversing out of a car parking space. Blind and partially sighted people are most at risk, but so are the young and elderly. Requiring retrofitting should prevent many accidents.