The UK Government is facing growing pressure to modernise drug-driving laws and allow police to use evidential saliva tests at the roadside.

Campaigners argue that this move could save lives and close legal loopholes that allow offenders to escape justice.

Currently, police can only use roadside drug tests as an initial screening.

High time

There are new calls for the government to amend drug driving laws, in particular, the use of roadside drug testing kits and the reliability of results.

If a driver tests positive, officers must obtain an evidential blood sample, which is not always possible.

Even when samples are taken, laboratory delays of up to six months mean offenders can continue driving while awaiting results.

Some offenders evade justice entirely if the tests are not processed within six months—the legal deadline for road traffic offence prosecutions.

Rising tide

Drug driving is regarded as an escalating problem on UK roads.

However, it is not a clear picture as te laws were only brought in 2015, so data is limited and also affected by the frequency of testing by the police and the effective understanding and use of law.

But recent statistics paint a troubling picture:

  • More than half of drivers stopped on suspicion of drug driving fail roadside tests. According to a Freedom of Information (FOI) request submitted by IAM RoadSmart, 51% of drivers tested positive in 2023, while 49% failed in the first seven months of 2024.
  • Drug-related road deaths have hit a five-year high. Figures revealed in the House of Lords show that between 2022 and 2023, the number of drivers killed while under the influence of drugs rose from 96 to 144—a 50% increase in just one year.
  • The Department for Transport (DfT) reports that the number of deceased drivers with ‘impairment drugs’ present increased by over 70% from 2014 to 2022.

Closing loopholes

To mark the 10th anniversary of drug-driving legislation in the UK, motoring organisation The AA and roadside testing supplier Dtec International are calling for immediate reform.

They argue that permitting evidential saliva testing at the roadside—which has been successfully used in Australia for nearly 20 years—would streamline the prosecution process, reduce police costs, and remove dangerous drivers from the roads more swiftly.

Jack Cousens, Head of Roads Policy at The AA, stressed the urgency of reform: “Drug driving is fast becoming a major road safety concern which needs urgent action. Modernising the prosecution process can help take more dangerous drivers off the road while keeping costs down for police forces.”

The AA also supports hiring 1,000 more roads police officers alongside legal changes to improve enforcement and deterrence.

Dtec International’s Managing Director, Ean Lewin, strongly criticised the current system, calling it “a national disgrace”: “For over a decade, we have allowed a broken system to keep drug drivers on our roads while victims and their families continue to suffer. Right now, a driver who fails a roadside drug test can legally remain behind the wheel for up to six months—and if they plead not guilty, potentially for over a year.”

Urged to act

The Crime and Policing Bill, introduced in Parliament last week, presents an opportunity for reform.

Campaigners are urging ministers to include provisions for evidential roadside saliva testing in the legislation.

If this is not addressed in the Bill, they insist that the Home Office, Department for Transport, and Ministry of Justice must collaborate to enact legislative change through another mechanism.

With drug-driving fatalities rising and offenders slipping through the cracks, campaigners say the time for action is now. Reforming drug-driving laws could help ensure swifter justice, improve road safety, and prevent further loss of life.

Recently, Lilian Greenwood, the UK’s minister for the future of roads, has expressed interest in exploring new technologies to accelerate the prosecution process for drug driving offences.

Speaking in response to a parliamentary question from Andrew Snowden MP, Ms Greenwood highlighted the potential of a saliva-based testing system already used in countries like Australia and France.

The system involves collecting evidential saliva samples at the roadside from drivers who fail an initial DrugWipe test.

These samples are then processed in laboratories within days, enabling prosecutions to be completed in weeks rather than months.