Dehydration as bad as driving drunk
LOUGHBOROUGH — Failing to drink enough water before getting behind the wheel is the equivalent to driving while drunk.
A recent study showed that drivers who drank no more than 25ml - one metric tot - of water per hour made the same number of mistakes on the road as those who were over the blood-alcohol limit.
In each case, the number of mistakes made was twice the number made by well-hydrated motorists.
Researchers at Loughborough University said the change was evident in those who were only deemed “mildly dehydrated”.
Ron Maughan, professor of sport and exercise nutrition, said the study showed that dehydration was an “unrecognised danger” for drivers.
“We all deplore drink driving, but we don’t usually think about the effects of other things that affect our driving skills, and one of those is not drinking and dehydration,” he said. “There is no question that driving while incapable through drink or drugs increases the risk of accidents, but our findings highlight an unrecognised danger and suggest that drivers should be encouraged to make sure they are properly hydrated.”
The research team, whose results were published in the Journal of Physiology and Behaviour, carried out tests on male drivers using a driving simulator.
Reduced brain activity Each volunteer used the simulator on a day when they were hydrated - which involved drinking 200ml (less than a cupful) every hour. The tests were then repeated on a “dry day”, when the participants were given just 25ml of water an hour.
The test included a simulated two-hour monotonous drive on a dual carriageway, with slow-moving vehicles which had to be overtaken. During the normal hydration test, there were 47 driving errors. That number rose to 101 when the men were dehydrated - the same mistake rate as that seen when drivers were either sleep deprived or at the blood-alcohol limit.
The researchers, who said driver error accounted for 68 percent of all vehicle crashes in the UK, concluded that dehydration led to reduced brain activity, as well as a drop in alertness and short-term memory.
Each of the 12 participants in the study was an experienced driver who had held a driving licence for more than two years, driving at least two hours per week.
The researchers wrote: “Mild hypohydration [dehydration] can cause symptoms such as headache, weakness, dizziness and fatigue, and generally makes people feel tired and lethargic, with lower self-reported ratings of alertness and ability to concentrate.
“Body water losses have been shown to impair performance in a variety of tests of both physical and mental performance.”
They added: “The level of dehydration induced in the present study was mild and could easily happen to drivers with limited access to fluid over the course of a busy working day.”
The team called for a public awareness campaign to encourage drivers to keep themselves hydrated.
They wrote: “There is no question that drink driving and driving while tired increases the risk of road accidents.
“Given the present findings, perhaps some attention should also be directed to encouraging appropriate hydration among drivers.’ — Daily Mail
Drivers who had consumed alcohol over the legal limit as well as drivers who were dehydrated made twice as many driving mistakes as those who were hydrated.