By Daniel Machin
Motorists who use properly-prescribed medication will not be penalised by the new offence of drug-driving, the Government has pledged.
Transport Minister Stephen Hammond made the promise as he published a Whitehall-commissioned report on drug-driving.
The new offence of driving or being in charge of a motor vehicle with a specified controlled drug in the body is included in the Crime and Courts Bill, currently before Parliament.
Mr Hammond acknowledged that the design of the new offence must send a strong message in order to act as a deterrent.
But at the same time he pointed out it was important to consider the position of drivers who legitimately and safely use medicines which may contain controlled drugs.
The 200-page report - by a panel of medical and scientific experts from King's College in London - suggests thresholds at a level above which driving is considered dangerous.
For example, for morphine it recommended a drug-drive limit that is well above the concentration of morphine in the blood that a cancer patient might have been prescribed in the long-term.
In addition, the experts want to see a dual limit when some drugs are discovered in combination with alcohol, as previous evidence has shown that this significantly increases the risk of a traffic accident compared to when driving under the influence of low concentrations of a single substance on its own.
They also believe that the Government should copy a successful system implemented in Norway, which involves routinely collecting blood samples at all traffic accidents on the road and analysing them against a list of universal substances.
The panel said that these results should be held in a national database to provide "much-needed evidence of the consequence of drug-driving".
"The Government will carefully consider the panel's recommendations," said Mr Hammond.
"We recognise that for the purposes of drug testing, distinguishing between those drugs which do have medical uses and those which do not is complex.
"We must ensure that the new offence would not unduly penalise drivers who have taken properly prescribed or supplied drugs in line with medical advice."
Drug-driving could be a factor in as many as 200 deaths a year on the roads, according to Dr Kim Wolff of King's College's pharmaceutical science department, who led the panel of experts.
She claimed it should be a priority to raise awareness among the general public about the risks associated with drug-driving, especially when drugs are consumed with alcohol.
Meanwhile, AA president Edmund King has welcomed the new offence of drug-driving.
The AA has highlighted the danger of drug-driving for years, and Mr King believes it is about time that something was done to tackle the problem.
"Ultimately the success of any new offence will be down to police enforcement, education and resources, he added. "We hope that the new offence will deter drug drivers from driving with any level of illicit drugs in their system."
Later this year the Government is to make specific proposals regarding the drugs to be specified in regulations for the new offence, although these proposals are to be subject to a public consultation.