This paper presents an EEG-EOG based alertness detection system for vehicle drivers. As lots of algorithms based on signal processing of EEG, EOG, facial EMG & facial gesture image processing. Though these have disadvantages that complex in nature. Our algorithm is based on measure of time duration between blink movements of eye. Normal time duration between eye blink patterns is measured by several observations. Algorithm is set such that If the time duration between blink patterns is more than normal than person may napped or not in alert stage. The basic EEG-EOG acquisition system is made and time duration algorithm set through signal processing tool kit in mat lab. Time duration between blink signals crosses the sated reference time that means driver is obviously in abnormal stage maybe in napped or fatigue condition. However both dangerous for driving. We can also design simple hardware, just measuring time duration between two consecutive picks of blink signal which is as same as measure of ECG R to R interval circuit and when we find time duration just beyond reference time we have to trigger on devices that make driver alert or we can give that impulse to device such as energy pulse generator, speaker to make driver alert and that can easily prevent threats of sudden accident.