Lorry driver Colin Wrighton had been suffering obstructive sleep apnoea
A coroner has vowed to lobby the government to reduce the number of road deaths caused by a sleeping disorder.
Merseyside Coroner Christopher Sumner announced his intention while passing a verdict of accidental death at the inquest of Toby Tweddell.
Mr Tweddell, 25, from Sale, Greater Manchester, was killed when a lorry driver ploughed into a queue of traffic on the M62 in Merseyside in 2006.
Lorry driver Colin Wrighton had been suffering obstructive sleep apnoea.
The 54-year-old's condition had yet to be diagnosed but he had complained to his doctor about feeling tired four months before the accident.
Tests had been run for diabetes, which came back negative.
Obstructive Sleep Apnoea (OSA)
OSA is a respiratory condition in which the throat repeatedly narrows or closes during sleep
Air is blocked from getting into the lungs, and low oxygen levels cause the brain to wake the person up
It is associated with an increased risk of accidents at work and on the road, due to tiredness
OSA affects about one in 25 men and one in 50 women between the ages of 30 and 60
Being overweight, smoking and drinking alcohol increases the risk
Many people are unaware they have it
It was not until after the crash, at the Rocket Interchange on 8 August 2006, that obstructive sleep apnoea was first considered.
The condition causes the upper airways to repeatedly close during sleep, and sufferers constantly wake up to breathe, leaving them tired the next day.
Mr Wrighton was initially charged with causing death by dangerous driving, but the Crown Prosecution Service offered no evidence against him after his sleeping condition was revealed.
In giving his narrative verdict, which was released as a statement, the coroner said: "It is my intention to prepare a Rule 43 Report to the Lord Chancellor concerning obstructive sleep apnoea in an endeavour to reduce the number of deaths that arise annually from this condition."
Mr Tweddell's parents, Nic and Monica, want compulsory screening of sleep apnoea introduced for all professional drivers, claiming that more than 80% of sufferers could be undiagnosed.
In a statement, they said: "We are pleased that the coroner will be alerting the government to the dangers of sleep apnoea, and we look forward to seeing the details of his report.
"We will be working hard in the coming months to ensure that the coroner's recommendations are acted on by government."
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