Abstract: By using subassemblies that can be mounted on the floor of the vehicle or on the brake lever and the accelerator lever a continuously active and quick acting alerting system is developed in which an operator sets a time which is needed to switch over the foot between the accelerator and brake pedals and when operator does not accelerates or apply brakes uses an auxiliary device which can be operated by the same foot to indicate alertness and failure to do so within the set time results in actuating alarming devices. Whenever the accelerator or the brake pedal or the auxiliary device is actuated the timer resets itself. The time set is usually within five seconds.