The latest example is the Nissan ECO-pedal system, which will be available in models starting next year. Although the company says they have no "test mules" (e.g., car prototypes) anywhere in the world, they have tested the ECO-pedal in their lab. When the driver accelerates too much, the ECO-pedal system pushes back – automatically slowing down the driver to save fuel. There's also a visual indicator: a green ECO-P light emits from the speedometer and it flashes when fuel economy is degrading faster. Burn rubber too fast, and the ECO-pedal light will flash and turn yellow as a warning.