Police uses saliva test to detect sleepiness

Driving when sleepy is dangerous. That is why the police will check on sleepiness using a saliva test. Drivers are free to take the test.

‘Unexpected killer’

“Sleepiness is an unexpected killer,” says Werner De Dobbeleer of the Flemish Foundation for Traffic Science (Vlaamse Stichting Verkeerskunde, VSV). “It plays an important role in one out of five serious accidents, just like alcohol.”

Drivers will not be forced but are free to take the test. The police officers just need a sample of saliva that will be sent to a lab where the presence and amount of melatonin is analyzed. “Melatonin is a hormone that reflects your biorhythm. It tells your body when it’s time to go to sleep,” explains sleep scientist, Marijke Gordijn. “The amount of melatonin shows whether you can drive safely or not.”

Social jetlag

Those who participate also have to fill in a questionnaire to detect whether they’re early birds or night owls. The question list also tries to discover people’s social jetlag, or the difference between their sleeping pattern during the weekend and on weekdays.

All this information determines someone’s optimal time for bed. Ignoring it is not a good idea because our functional behavior deteriorates. Neglecting our body’s signal of sleep is as bad as driving with 0,5 percent of alcohol in our blood.

The VSV hopes to have at least 400 volunteers to take the test between 10 p.m. and 2 a.m. when our biorhythm is the lowest. The main goal of the action is to map the situation in Belgium: how sleepy is the Belgian driver? The results will be presented in February.

Useful tool

A do-it-yourself test is not available yet, although it would be a useful tool for drivers who often drive at night. “Knowing when you’re too tired to drive is very difficult to determine,” explains sleep expert Johan Verbraecken. “Experiments with a driving simulator showed that drivers don’t feel the exact moment they’re actually falling asleep.”

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