All automobiles have a brake pedal which is used to slow down the vehicle and shift to a lower gear or halt the vehicle completely. It is very important that the stop light behind the vehicle is turned on instantly, even before the vehicle actually starts slowing down, to give the maximum reaction time to vehicles following. A magnet is fitted behind the brake pedal and a reed sensor is mounted very near the magnet. When the brake pedal is not pressed, the magnet keeps the reed sensor in an actuated state, but when the brake pedal is pressed, the magnet is the first to move away from the reed sensor, even before the brake pedal actually works on the brake pads. This early signal is used to trigger the tail lamp and gives vehicle ample time to react. An added benefit is that the same signal can also be used to turn off cruise control. Molded reed sensors such as the R3 or PCB mountable reed sensors such as the MS-105 or MS-106 are suitable for this application.