The absolute minimum is not fought. It is waited out.
At 4, the body is at its lowest point of the day. Core temperature falls to its minimum and alertness follows. Reflexes slow down: at 100 km/h, half a second is 14 metres. Between 2 and 6, sleepiness-related crashes are the most frequent. It is not weakness, it is the body's rhythm, and the body is right.
Details 48 s · 9:16 · four languages · generated and declared images · 2026-09-06 · Drive Awake
At 4, the body is at its lowest point of the day.
Alertness follows a 24-hour rhythm that does not depend on willpower: around 4 it reaches its lowest point. On an empty road the body makes no exception.
Wright, Hull, Czeisler 2002 · DOI 10.1152/ajpregu.00205.2002
Watch this passage (0:00) →Core temperature falls to its minimum. Alertness follows.
During the night core temperature drops by about half a degree and reaches its minimum between 4 and 5. Alertness follows the same curve: the dashboard cannot see it, the body can.
Kräuchi, Wirz-Justice 1994 · DOI 10.1152/ajpregu.1994.267.3.R819
Watch this passage (0:07) →Reflexes slow down. At 100 km/h, half a second is 14 metres.
At 100 km/h you cover 28 metres every second. Half a second more to react, and braking starts 14 metres further on: the length of three cars.
Watch this passage (0:14) →Between 2 and 6, sleepiness-related crashes are the most frequent.
Sleepiness-related crashes cluster between 2 and 6, when traffic is lightest. Stopping at a rest area is the choice the body is asking for.
Horne, Reyner 1995 · DOI 10.1136/bmj.310.6979.565
Watch this passage (0:20) →
It is not weakness. It is the body's rhythm, and the body is right.
It is neither weakness nor distraction: it is physiology. Stopping and resting is the right answer, not a failure.
Watch this passage (0:27) →The episode's message, spoken and written on screen, comes before the signature.
2026-09-06 · Drive Awake
