The driver who can admit tiredness protects more than their own arrival.

Saying you are too tired to drive costs something socially: it delays everyone, it admits a limit, and it can feel like letting the group down. Which is why it is hard, and why so many people keep going. But the risk you carry is not only yours, and neither is the arrival. Naming a limit out loud is one of the few moments where a small embarrassment stands in for a large harm.

If you are the tired one, say it plainly and early rather than negotiating with yourself for another twenty miles. If you are the passenger, ask in a way that makes the honest answer easy.