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Sleep Science
What happens when sleep is missing, and what changes at the wheel?
Sleep is not a passive state. It is the work that keeps attention, perception and readiness in order. Sleep Science is the section where Drive Awake brings this science to the road: the disorders that affect it, how sleepiness is measured, the body's rhythm that decides when it weighs most. Research, interviews and documentary development, always with the sources.
The twenty-four hours, in one figure
FEDRO dataWhen alertness falls, and how many people are on the road at that moment.
alertness, circadian rhythm traffic, Gotthard tunnel night 20-04 threshold 05 and 18-19
At three in the morning, in the hours when alertness is at its lowest, one hundred and eighty-five vehicles an hour, still pass through the Gotthard tunnel, two hundred and twenty-nine at Biasca, three hundred and fifteen at Lugano. The road at night is not empty.
Open the tool → See the full data →
Traffic: Federal Roads Office FEDRO, 2022-2025, valid counting days · Alertness: Horne and Reyner 1995, DOI 10.1136/bmj.310.6979.565
Last revision: 19.07.2026
| 19.07.2026 | Disorder OG images redrawn and unified |
| 18.07.2026 | From six to fourteen disorders in five families |
| 17.07.2026 | Four-part home and app access from the tool |
| 11.07.2026 | Typographic revision of contents |
| 10.07.2026 | Link to the Perspectives section |
What disturbs it
The sleep conditions that take attention from the wheel. Five families, one shared risk.
Five roads, one risk
The cause changes, the destination does not. Every family leads to the same point.
Why they matter at the wheel
At the wheel, missing sleep becomes sleepiness: it slows the gaze, lengthens reaction times, opens the door to microsleeps. Different disorders all reach the same point - vigilance giving way while driving. That is why we read them together, not as isolated cases.
Forensic · Road Safety
Obstructive Sleep Apnoea
Repeated interruptions of breathing during sleep, caused by partial or total obstruction of the upper airway.
In the HypnoLaus study in Lausanne, among people aged 40 to 85, at least moderate sleep-disordered breathing was found in nearly half of men and about a quarter of women; the authors note that current criteria are very sensitive (Heinzer 2015).Road Safety · Priority Focus
Sleepiness at the Wheel
One of the leading invisible causes of road accidents.
Up to 30% of serious accidents in evening and night hours are linked to sleepiness (Prof. Mauro Manconi, EOC).Neurological · Rare
Narcolepsy
A chronic neurological disorder causing intense daytime sleepiness and sudden sleep attacks; in type 1, strong emotions can trigger cataplexy, a sudden loss of muscle tone.
The form with cataplexy affects 2.5 to 5 people in 10,000 (Longstreth 2007).Behavioural · Most common
Acute Sleep Deprivation
Staying awake longer than usual builds an immediate sleep debt.
In the lab, after 17 hours awake, performance on a computer coordination task fell to the level seen at 0.05% blood alcohol, the Swiss legal limit; after 24 hours, to the level seen at 0.10%, well beyond it.Fourteen disorders documented across five families. The section keeps growing.
Where to turnWhen daytime sleepiness keeps coming backThe first step is your GP. For tests, Switzerland has 34 certified sleep centres.See the map →How it is measured
The clinical and biochemical path toward an objective marker of sleep deprivation.
How sleepiness is measured
Sleepiness still has no roadside test.
Five steps, the last under validation · IRM study, DOI 10.1021/acs.jproteome.5c01064 ActiveTired or sleepy?
The question to ask before you drive, and the two cases where the answer misleads.
On a motorway, after a short night · Philip et al. 2005, DOI 10.1016/j.aap.2004.07.007When it weighs most
The body's rhythm decides when sleepiness weighs most.
The clock within
At three in the morning and four in the afternoon, alertness drops, even if you have slept. It is not chance and it is not weakness. It is a clock the body carries within it, and willpower cannot move it.
Five scenarios A normal day · Up all night · Up all night, coffee at 2 am · Up all night, nap at 1 am · After a night shift
Pick a time and watch what happens →The journey, in seven stops
7 stops · 29 sources with DOI · two-process model (Daan, Beersma and Borbély 1984)
At three in the morning the road is not empty
FEDRO dataGrey is the daily peak, blue is three in the morning. Three counting stations on the A2, hourly means on valid days.
Source: Federal Roads Office FEDRO, automatic counting 2022-2025, valid counting days
The habits
The practical side: hygiene, substances, sleep and driving. Coming as Habits.
Coming to this section: Sleep hygiene · Supplements and substances · Sleep and driving.
