Over 2.8 million (7%) drivers admit to having operated a vehicle under the influence of banned substances in their lifetime, presenting a huge danger to other motorists, passengers and pedestrians.

The survey also highlighted drug-drivers have a distorted perception of their driving ability, even when they haven't taken drugs. Over a third (36%) of those who drive whilst under the influence of narcotics rated their driving ability as very safe or quite safe, with just 20% admitting they were a danger on the road.

Almost one-in-ten (8%) admitted they drove while under the influence of drugs as they didn't think they would get caught.    Other excuses include; drugs impairing their decision making process (7%), inability to find or afford a taxi (6%) and a lack of available public transport (4%).  

Drivers under the influence of drugs are literally "speeding", with one-in-twenty (6%) exceeding the speed limit. A further 6% were involved in accidents with other vehicles or incidents such as crashing into walls, while the driver was on drugs.

Andy Goldby, direct of motor underwriting at Direct Line Car Insurance, said: 'Drug driving is as irresponsible as drink driving.  The dangers of drug drivers on our roads are becoming increasingly apparent, with thousands admitting they have been involved in an accident while "high" or stoned. The effects of drugs can often leave people feeling overly confident or extremely relaxed, both of which are known to lead to dangerous driving behaviours. 

'We strongly support the Department for Transport's (DfT) decision to clamp down on drug driving and would welcome further investment in effective roadside drug tests to screen drivers the police suspect are under the influence of illegal or strong prescription drugs.'