For your own safety control of a stoplight to you should be carried out so often as soon as it is obviously possible.
PERFORMANCE ORDER
If you press a brake pedal, the wall of garage behind your car has to flash on the right and at the left light-red light.
At the movement in a column you can see in an internal rear-view mirror, whether both stoplights of your car are reflected in reflectors of headlights or in a varnish covering of the car following you.