If you encounter a driver who seems fatigued, what is the best action to take?

Advising a fatigued driver to pull over and rest is the best action because driving while fatigued significantly impairs reaction times, attention, and decision-making capabilities, similar to the effects of alcohol. Fatigue can lead to a higher risk of accidents as the driver may experience reduced vigilance and even microsleep episodes, where they briefly doze off without realizing it.

Encouraging the driver to continue driving can exacerbate the risk of an accident, as their level of alertness is already compromised. Offering them a drink does not address the primary issue of fatigue and could also lead to distractions. Asking them to switch drivers might seem helpful, but it's only effective if the new driver is alert and able to take over safely, which assumes they are not also fatigued.

The most responsible course of action is to ensure the driver’s immediate safety by recommending they rest until they feel awake and capable of driving safely again.