Drug driving: the law

Get your foot off the pedal and onto the facts.

What is it?

Drug driving is the term used to describe anyone who gets behind the wheel of a vehicle under the influence of any substance (legal or illegal) that is likely to impair their driving ability.

Under Section 107, Schedule 7 of the Railways and Transport Safety Act 2003:

• It's an offence to drive a motor vehicle while under the influence of a controlled drug;
• Police officers have powers to undertake roadside drug tests on drivers.

Penalties

Driving under the influence of drugs carries the same penalties as drink driving - a ban and a fine of up to £5,000 or up to six months in jail. If a person under the influence of drugs causes a fatal accident, they could face a two-year ban and a maximum of 10 years in jail.

Roadside testing

The law does not state any legal limit for drugs as it does for alcohol. This is because knowledge of how different drugs impair different people's driving ability is inconclusive. The extent of harm resulting from driving under the influence of drugs continues to be researched, although the current lack of a definite legal limit for drug driving can complicate any possible further prosecution.

If police officers suspect that you're driving under the influence of drugs, they can stop you on the roadside and observe you for outward signs of impairment caused by drug use. You'll probably be asked to perform a field impairment test, which involves testing your co-ordination skills. For example, you may be asked to close your eyes and touch your nose (as certain drugs can cause you to misjudge the position of your nose) or stand on alternate feet for 30 seconds while counting aloud (certain drugs, particularly stimulants, could cause you to count too fast or lose count altogether). The police officer will also check your pupils for unusual dilation - opiates (such as heroin and methadone) cause very small, 'pin prick' pupils, while stimulants (such as cocaine, ecstasy or speed) cause very large, 'saucer' pupils.

Refusal to participate in the tests is an offence in the same way as failure to provide a breath test under suspicion of drink driving.

Testing for the presence of drugs

Currently, police officers can only carry out roadside tests to judge impairment caused by drug use, rather than to detect the presence of drugs in a driver's body. A range of roadside testing devices to measure the presence of drugs in the body are being piloted, but impairment testing based on a standard biological test (such as the breathalyser test, which is used to indicate whether a person has consumed enough alcohol to impair their driving) is unlikely to be available for some time. This is because there isn't enough evidence regarding the impairing effects of drugs and their effects in different doses on different individuals, and because the technology to assess this is isn't yet adequate.

If you're taken to the station

If field impairment tests demonstrate that you may have been driving under the influence of drugs, you could be arrested and taken to the police station. Here, you may be tested for the presence of drugs through a biological test (for example, by testing a sample of your blood or urine). The police don't have to wait for you to sober up or resume consciousness in order to do this. A doctor can also carry out a blood test to see if you've been incapacitated due to medical reasons, such as illness or intake of prescribed medicine.

Prosecution

The law restricts prosecution to cases where police can prove that an individual is incapable of driving because of drugs. However, this is under review and police powers are likely to be toughened up following pressure from major driving and road safety organisations.

Before you take to the wheel

Drugs affect the way you think and behave, and this can have a significant impact on your sense of judgment and reaction times. We all know drinking and driving don't mix, and alcohol is a drug like any other. So be smart about drug driving, and think before you get behind the wheel or accept a lift from someone you know isn't in a state to drive.

Remember, possession of illegal drugs is an offence - you'll be landed with a heavy penalty (including a fine and/or prison sentence) for possession or intent to supply. 

Always read the label if you're taking prescribed medication. Antihistamines (often used in flu and hayfever remedies) and tranquillisers (used to treat anxiety, depression and sleeping disorders) may significantly affect reaction times and/or cause drowsiness. If the label advises against 'operating heavy machinery', consider it a warning not to get behind the wheel of a vehicle. If in doubt, consult your doctor (GP).