Which of the following actions should be taken if a driver feels fatigued?

When a driver feels fatigued, pulling over and resting is the most effective and safest action that can be taken. Fatigue significantly impairs a driver's ability to react quickly and effectively to road conditions, which increases the risk of accidents. Taking a break allows the driver to recuperate and regain focus, ensuring they can continue driving safely after adequate rest.

While other options, such as having coffee or opening a window, might provide a temporary feeling of alertness, they do not replace the need for actual rest. Increasing speed is particularly dangerous and counterproductive, as fatigue already slows reaction times and decision-making abilities, making it critical to prioritize safety by stopping to rest.