What is Drug Driving? 

Drug driving is driving while affected by drugs. This may include illegal drugs, prescription medicines and over-the-counter medicines. 

Many drugs can affect a person's ability to drive safely by impairing the ability to focus, make decisions, control movements and react quickly. This increases the risk of being involved in a collision.  

It is illegal to drive if you are unfit to do so because you have taken illegal or legal drugs. It is also an offence to drive with certain drugs above legal limits in your body, even if they have not affected your driving. 

While illegal drugs are often associated with drug driving, some prescription and over-the-counter medicines can also affect driving ability. Drivers should always check the advice provided with their medication and seek advice from a healthcare professional if they are unsure whether it is safe to drive. 

How drugs affect driving 

Driving requires concentration, good judgement and the ability to react quickly. Drugs can affect these abilities in different ways, depending on the drug taken. Common effects include slower reaction times, poor concentration, poor decision-making, and difficulty judging speed, distance or hazards. 

Illegal drugs can have a range of effects on driving. For example, cannabis can slow reactions and affect concentration, while cocaine may lead to overconfidence and taking more risks. Some drugs can also cause tiredness, confusion, anxiety or paranoia, which can further impair a person’s driving ability.  

Prescription and over-the-counter medicines can also affect the ability to drive safely. Some medicines may cause drowsiness, dizziness, blurred vision or difficulty concentrating. In some cases, a person may not recognise how much they have been affected.  

The effects of drugs can continue after the immediate feeling of the drugs’ effects have passed. Some substances may remain in the body for a long time, and lasting effects such as tiredness or reduced concentration can still affect the person’s ability to drive safely.  

Alcohol and drugs are a particularly dangerous combination. When taken together, their effects can be greater than either substance alone, increasing the risk of impairment and being involved in a collision.  

The penalties for drug driving are severe and can include: 

• A minimum 12-month driving ban 
• An unlimited fine 
• Up to six months' imprisonment 
• A criminal record 

Drivers convicted of causing death by careless driving while under the influence of drugs can face much longer prison sentences.

Medicines and Driving 

Some prescription medicines and over-the-counter treatments can affect a person's ability to drive safely. This can include medicines used to treat pain, anxiety, sleep disorders, hay fever, coughs and colds, among other conditions.  

The effects vary depending on the medicine and the individual, but may include: 

• Drowsiness 
• Dizziness or feeling light-headed 
• Blurred vision 
• Difficulty concentrating 
• Reduced coordination 
• Slower reaction times  

Some medicines can affect driving shortly after they are first taken, when the dose is changed, or when combined with alcohol or other drugs. In some cases, a driver may not recognise the extent to which their driving is affected. 

Drivers should always read the information leaflet supplied with their medicine and follow advice from their doctor, pharmacist or other healthcare professional. If a medicine carries a warning that it may cause drowsiness, drivers should assume that it could affect their ability to drive safely.  

It remains illegal to drive if a prescribed or over-the-counter medicine impairs driving ability. However, drivers taking prescribed medicines in accordance with medical advice may have a legal defence to a drug-driving charge involving certain specified medicines, provided the medication is being taken as directed and their driving is not impaired.  

Advice for drivers 

Drug driving is preventable. Whether using illegal drugs, prescription medicines or over-the-counter treatments, drivers should ensure they are fit to drive before starting a journey.  

To reduce the risk of drug driving: 

Never drive if you feel impaired by drugs or medication. 

Read the patient information leaflet supplied with any medicine, and if warnings are included that the medication could affect your ability to drive safely, assume that it will do so. 

Follow the advice of your doctor, pharmacist or other healthcare professional. 

Check whether a medicine may cause drowsiness, dizziness or affect concentration. 

Do not mix drugs and alcohol, as this can increase impairment. 

Consider alternative transport if you are unsure whether you are fit to drive.  

Drivers should not assume they are safe to drive simply because they feel well. Some drugs can affect judgement and concentration without the user being fully aware of the impact on their driving ability.  

Employers also have a role to play in preventing drug driving. Organisations whose staff drive for work should have clear policies on drugs, alcohol and medicines, and ensure employees understand their responsibilities when driving on work-related journeys.  

RoSPA's Position 

RoSPA supports measures to reduce drug driving and improve road safety. The introduction of drug-drive limits has provided an important framework for tackling the problem, but legislation alone will not prevent people from driving while impaired. 

Effective enforcement is essential. RoSPA calls for continued investment in roads policing and enforcement activity to help identify and deter drug-driving offences. 

RoSPA also believes that employers have an important role to play. Organisations whose staff drive for work should have clear policies on alcohol, drugs and medicines, and should ensure that employees understand their responsibilities for driving safely on work-related journeys. 

Greater public awareness is also needed. Many people are aware of the risks associated with illegal drugs and awareness campaigns should continue, but less understanding may exist around the effects that some prescription and over-the-counter medicines can have on driving ability. Drivers should be encouraged to understand how any substance they take may affect their fitness to drive. 

Through a combination of effective enforcement, employer engagement and public education, drug-driving collisions can be prevented and road users better protected.