More than half the drivers killed in road accidents in one police force area this year had illegal drugs in their system, according to figures from the RAC Foundation.

The samples from Durham Police suggest that in 50% of fatalities the victims had traces of either cannabis, cocaine, ecstasy or another prescription drug.

Many motorists are surprisingly ignorant of the dangers posed by drug driving

Sue Nicholson, RAC Foundation

The RAC says the figures are "shocking" and that they show many drivers are ignorant of the dangers of drug driving.

Durham Police took blood screenings from 23 people killed in road accidents, since the beginning of the year.

'High on drugs'

The RAC Foundation said it was concerned at the high number of drug-related road deaths - particularly given the government's intention to reclassify cannabis from class B to class C.

Sue Nicholson, head of campaigns for the RAC Foundation, said: "These results are shocking.

"They would suggest that even more motorists are getting behind the wheel when high on drugs than anyone previously expected."

Previous research suggested 20% of road deaths involve drugs, she said.

Law changes

"But these findings imply that the problem is becoming a more prevalent one than drink driving."

At the moment, police officers have no effective roadside technology to detect drugs, relying instead on recognition tests, observation and experience, she added.

"If the problem gets any worse then they may struggle to cope.

"Hence it is vital that any change in the law on cannabis is combined with a very high-profile, multi-media campaign.

"Many motorists are surprisingly ignorant of the dangers posed by drug driving."

Earlier this year the British Medical Association called on the government to co-ordinate scientific research to establish effective drug testing devices as soon as possible.

It says drugs - both illegal and legal - can affect the ability to drive safely.