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

The combination you selected is correct because both heavy eyelids and frequent yawning are clear indicators of fatigue while driving.

According to German traffic regulations, drivers must be in a fit state to operate their vehicles safely. Recognizing signs of fatigue is crucial, as it helps prevent accidents that can arise from drowsiness. Heavy eyelids signal that your body is ready for rest, while frequent yawning suggests that your brain is not receiving enough alertness to operate the vehicle safely. Accurately identifying these signs allows drivers to take necessary precautions, such as taking breaks or seeking rest, thus promoting road safety for everyone.