In the early 1990s the Sleep Research Laboratory at Loughborough University of Technology, in collaboration with Leicestershire police, conducted a study on sleepiness among people driving on Midlands motorways. Reported accidents were clustered in three periods of the day – midnight to 2am, 4am-6am, and 2pm-4pm, with the 4am-6am being the most risky period. Someone driving between 4am and 6am was 13 times more likely to have a sleep-related accident than someone driving between 10am to noon, or from 8pm-10pm.

The researchers indicated that, given the lightness of traffic on roads in the early hours, the incidence of accidents between 4am and 6am was about seven times as great as it was for other times of the day. The Loughborough team also discovered that the total time the sleep-related accident driver had spent behind the wheel was not as important as how much they slept.

A poll carried out last year by the RAC Foundation showed that more than 60% of drivers questioned said they had driven while sleepy. Of these, 8% said they had, at some time, nodded off momentarily at the wheel. Thirty per cent also said that they felt more stressed, angry and more likely to confront other drivers when they were tired. “We now need action to implement a range of plans which will stem these avoidable deaths and injuries,” said the foundation’s executive director, Edmund King.

The RAC Foundation yesterday called for more rest and recreation areas along motorways and trunk roads, further studies into the causal factors of sleep related accidents, more tiredness warning signs on motorways, and more research into sleepiness detectors for fitting into cars. These detectors can emit an alarm when the driver is showing the first sign of drowsiness. Car manufacturers are looking into the possibilities of introducing them.