Being dehydrated while driving may mean you make as many mistakes as drivers who have drank alcohol, a new study suggests.
Reachers found that drivers who only had 25ml of water per hour (around five sips) made twice the amount of mistakes compared to drivers who had stayed hydrated throughout their journey.
What is perhaps even more surprising is that dehydrated drivers made the same amount of mistakes as drivers tend to when they have consumed alcohol and are over the drink driving limit.
Professor Ron Maughan, who led the study at Loughborough University, told The Telegraph: "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."
A group of volunteers completed a range of tests over two days using a laboratory-based driving simulator in order for the researchers to draw their conclusions.
On the first day, the participants were provided with 200ml of fluid per hour. On the second day, participants experienced mild dehydration and were permitted to drink only 25ml per hour.
The researchers monitored "driving errors" made by participants, including late braking and drifting across the lane.
They recorded 47 driving errors on the day when participants were hydrated. This number rose to 101 on the day when participants were dehydrated - more than double the previous amount.
The scientists concluded that even mild dehydration was likely to lead to a reduction in concentration levels when driving.
"The level of dehydration induced in the present study was mild and could easily be reproduced by individuals with limited access to fluid over the course of a busy working day," they wrote.
Government figures indicate that in 2012, 230 people were killed as a result of drink driving. This means that alcohol was responsible for about 12% of all road deaths.
The NHS recommend that the safest option is not to drink any alcohol at all if you plan to drive, as even a small amount of alcohol can affect your ability.
They say there is no definite way to tell whether you are within the legal limit - alcohol’s effect on the body varies from person to person.
The latest Loughborough University study suggests we should be paying attention to the amount of water we consume, as well as the amount of alcohol, when driving.
The study is published in the journal Physiology and Behavior.
H/T: The Telegraph