Which of the following is a sign of drowsy driving?

Frequent yawning and heavy eyelids are strong indicators of drowsy driving. These physical signs suggest that the driver is struggling to stay awake and alert, which can significantly impair their ability to operate the vehicle safely. Drowsiness can lead to slower reaction times and reduced awareness of the environment, increasing the risk of accidents. Recognizing these signs is crucial for drivers to take necessary actions, such as pulling over to rest or taking a break, to ensure their safety and the safety of others on the road. Other options like checking mirrors, listening to loud music, or driving at higher speeds do not directly relate to drowsiness and may indicate different behaviors or driving styles, but they are not reliable indicators of fatigue.