Auto hazard warning light

When a car reverses the hazard warning lights should flash automatically namely to assist the driver in safe reversing. He doesn't always remember to do it manually.
But how many times especially during daylight hours or any other time does it become a hazard to other drivers, a prime example is reversing out of a parking lot at a local Mall or supermarket.
Solution, if the hazard warning lights were activated automatically then everyone would see the impending problem as often the driver is unsighted or in the car alone.
The solution it could be wired into the existing reversing light switch, the usual switch for manual operation unaffected.
It is a simple solution that would improve road safety and be a massive advantage to the driver.
Most drivers forget and do not use the hazards this way they don't have the chance to forget.