text: If they have a phone use the safe while not driving button. That way messages and calls will not come in and let others know they are driving and will call when its safe.   Do you really want a machine that tells you how you feel? If so why would you want a machine telling if you know how you feel like. These type of technology is not good and theres no need in having it mostly not in a classroom or school where anything could happen to it if you not carefull.