Experts divided on ethics of testing and punishing tired drivers

Development of biomarkers to detect sleepiness could affect the way we use vehicles - and even how we work

• Blood test for sleepy drivers could pave way for prosecutions
• How to reduce the risks of sleepy driving

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.