How can you tell that you are getting tired while you are driving?

You correctly identified heavy eyelids and frequent yawning as signs of tiredness while driving. In German traffic safety, these are common physical indicators that your alertness is decreasing, which can impair your ability to react quickly and concentrate. Quicker reaction time is not a sign of tiredness; in fact, tiredness usually causes slower reaction times. Recognizing these signs early helps you take a break or rest, reducing the risk of accidents caused by fatigue.