Blood tests are widely used to determine if a driver who has caused an accident has been consuming alcohol or drugs. But scientists are split on the ethics of penalising drivers who drive dangerously because they haven’t got enough sleep.
At the moment, drivers are largely left to judge for themselves whether they are too tired to drive, but the development of biomarkers to detect sleepiness could change that, and make it easier to prosecute drivers who cause an accident because they are impaired due to sleep deprivation.
There is no doubt that drowsiness kills. In Scotland, which recently launched a national campaign to raise awareness of the issue, fatigue is a contributory factor in about 50 fatal and serious injuries each year. Worldwide, between 10% and 20% of all road crashes are estimated to be fatigue-related.
In the UK, a tired driver who kills someone can be charged with death by dangerous driving or death by careless driving. Professional drivers of goods and passenger road vehicles must maintain logbooks, record hours of work and rest, and many commercial fleets use event data recorders, which police can study if a vehicle is involved in a crash. Yet proving that a crash was caused by driver fatigue is still an onerous task.
The biomarker-based test being developed by researchers at Monash University in Australia detects byproducts of metabolism from various organs in the blood. A similar test that focuses on stress responses in red blood cells when somebody is sleep-deprived is being developed by Prof Simon Archer at the University of Surrey in Guildford. “These are the products of genes that are working overtime because that person isn’t sleeping and their cellular machinery is pumping along when it should be in downtime,” Archer said.
A Swiss team at the University of Zurich is also examining whether biomarkers of sleepiness can be detected in saliva, exhaled breath, or sweat.
Such tests could help prove if someone’s erratic driving was connected to fatigue. They could also be used preventively, particularly in sectors such as road haulage or aviation. “If you’re a commercial pilot, we accept as a society that it is critical that you’re fit for duty, so you could take a test before you come on duty, which could tell you whether you’re at risk over the next eight hours,” said Shantha Rajaratnam, a professor of sleep and circadian medicine at Monash University in Melbourne, and chair of the Sleep Health Foundation.
Yet, while most sleep researchers agree that more needs to be done to reduce deaths and injuries caused by sleepy driving, some question whether penalising drivers is the best solution.
“If you refuse to work because of a shift schedule, or you are not allowed to work and not paid because you are too sleepy, that is directly affecting your income,” said Dr Gilles Vanderwalle, a neuroscientist at the University of Liège in Belgium, who studies sleep and wakefulness. “While I agree that we have the techniques to detect drowsiness, we even have the techniques to predict vulnerability to lack of sleep and could maybe start advising people, based on their genetics or their profile, not to take a job – having the choice of a job is still largely the luxury of people with a good socioeconomic status.”
Dr Daan van der Veen, a senior lecturer in sleep and chronobiology at the University of Surrey, said: “I believe that addressing the root cause of this problem, eg shift work and long working hours, and alleviating the negative effects of this by adopting better working schedules or other remedies is a better approach for the individual and society in the long run, rather than penalising individuals after the damage has been done. Especially considering that this loss of sleep, or poor quality sleep due to work or personal situations, is not always a choice, whereas drinking alcohol is.”
