Lifting your foot off the accelerator in a Nissan Leaf triggers brake lights when in e-Pedal mode (one foot driving, no need to use the brake pedal except in an emergency). It reminds me of a feature that car manufacturers declined to install (due to cost) many years ago, in which brake lights would be triggered by rapidly taking your foot off the accelerator. The idea was that this scenario would usually be followed by emergency braking and that anyone following would see the brake lights come on a fraction of a second earlier.