The Heat is On: Dehydration Causes Driver Errors

With heat records shattered in Germany, France, and The Netherlands, it may be time to fine tune the “don’t drink and drive” message that is a pillar of safe driving practices – but don’t pop open a beer to celebrate. According to a recent report, drivers who are dehydrated make as many errors on the road as drivers with 0.08% blood alcohol levels, the legal limit for drunk driving in the UK, the US, and many other countries.

The first study into dehydration, driving errors and accident risk was led by Professor Ron Maughan of Loughborough University in London and published in the journal Physiology and Behavior. In the study, mildly dehydrated drivers – those who had up to five sips (25 ml) of water per hour – made over twice as many driving errors as they did when properly hydrated. The errors included lane drifting, late braking, and touching or crossing a rumble strip or lane line.

Dehydration results in impaired mental functioning, leaving drivers less alert, less able to concentrate, and with worse short-term memory. Drivers in the study also reported headaches and fatigue.

The study results underscore the importance of maximizing safe driving practices. Drivers should be encouraged to drink sufficient quantities of water, especially during hot summer months. In addition, in-vehicle feedback systems should be used to alert drivers – and their managers — to slippage in driving behavior that might indicate dehydration. And while there is no substitute for focus, drivers who have internalized safe driving practices will be more likely to subconsciously maintain safe behaviors even under adverse conditions.

GreenRoad exception alerts enable managers to learn about unsafe driving behavior in real time, and act to get an impaired driver off the road – regardless of the root cause of his impairment. The system also provides easy hours of service logging to help prevent driver fatigue.

This summer, improve your fleet’s safety record by making sure that your drivers do drink (water) when they are driving.