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Scientists Warn Of The 'Unrecognised Danger' Of Dehydrated Driving

By raccars Published

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A new study suggests that driving while dehydrated could be as dangerous as drink driving. Research carried out at Loughborough University, showed that even mild dehydration can lead drivers to make twice as many mistakes while behind the wheel.

Researchers concluded that drinking only 25ml of water per hour could be considered the dangerous dehydration point, leading drivers to make as many driving errors as those who had been drinking alcohol, compared to the number of errors made by well hydrated drivers.

Dehydration can cause brain function to be impaired, mood changes, fatigue and headaches plus reduced alertness, concentration and short term memory, according to the scientists carrying out the research, which focused on the effects of dehydration on driving errors and accident risk. The results of the study were published in the journal 'Physiology and Behavior,' detailing the two day testing process carried out on male drivers in a driving simulator.

Each test subject took three simulated drives on each of the two days, on one of which they were hydrated and on the other had not drunk enough water. Tasks included in the test were a two hour drive on a monotonous dual carriageway featuring a hard shoulder, bends, simulated rumble strips and a requirement to overtake slow moving vehicles. On the dry day, the test subjects were allowed to drink only 25ml of water per hour and on the hydrated day, they were given 200ml of water every hour.

Errors measured on the simulated drives included late braking and lane drifting. Comparisons between the results showed driving errors increased dramatically on dry days, from 47 under hydrated conditions to 101, on average. The error rate was highest during the last quarter of the two hour test, showing how concentration decreases with dehydration.

Scientists claim that the levels of dehydration their conditions produced were not extreme and could easily occur on any busy day. Dehydration can cause a drop in weight of up to 2%, and a significant amount of water can be lost from the body simply by driving in a hot car. With 68% of accidents caused by driver error, the scientists involved in the research are very worried that even mild dehydration could be a contributory factor, particularly for drivers who deliberately avoid taking in water on a long journey to reduce the number of toilet stops.

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