Distracted driving and drowsy driving are the main causes of car accidents. We proposed the Distracted Driving Decision Algorithm (DDDA) proposed whereby binary results from blink detection and gaze estimation are computed with the sliding window algorithm. The proposed algorithm is expected to be efficient in a vehicle environment system. The DDDA runs based on computational algorithms instead of using a machine learning model; ultimately, the process of determining the status of a driver can be performed in an efficient and accurate way. The average accuracy of the algorithm and time for it to process one frame was 83.5% and 42ms respectively. By improving the accuracy, the DDDA can contribute to provide easier access to the DMS (Driver Monitoring System).