Alcohol, drugs and driving – Section 5A six years on Speaker: Prof Atholl Johnston

Date: 29/04/21

Time: 6.30pm

Venue: Webinar


To view the presentation please either click on the link below or the video window below.

In 2012, Prime Minister David Cameron set out to reinforce UK road traffic legislation in response to increasing incidence of drug driving affecting road safety. The aim was to help police enforce Section 4 of the Road Traffic Act, so as to be better able to demonstrate beyond reasonable doubt that a driver was unfit to drive through drink or drugs. Professor Johnston was appointed to two expert panels convened by The Department for Transport (DfT) and The Home Office to look at the evidence and to advise on which drugs to include within legislation and at what blood level limits to set the specified concentration values. Following the advice of these panels, per se concentration limits for driving were set for seventeen drugs and new drug driving legislation came into force in March 2015, taking on board many of the panels’ recommendations. The impact of the legislation has been profound. On 27 August 2017, a report evaluating the effectiveness of the first year of implementation found that the Government legislation on drug driving is working ( The new offence has led to additional police activity against drug drivers, and higher prosecution and conviction rates. Section 4 offence conviction rates have been approximately 80% since 2012, and in 2015, proceedings brought for Section 5A offences had a conviction rate of 98% – which is comparable with drink-driving (96%). The introduction of the Section 5A drug-driving offence has resulted in over 40,000 additional convictions for drug-driving


Professor Atholl Johnston Professor Johnston is the Science Director for Analytical Services International, Professor Emeritus of Clinical Pharmacology at Barts and The London School of Medicine and Dentistry, Queen Mary University of London and visiting Professor of Forensic Pharmacology and Toxicology at King’s College London. He has over 300 publications in the peer reviewed journals indexed by PubMed. In a recent independent analysis of the citation impact of approximately 7 million scientists publishing across 22 different research areas worldwide, Professor Johnston’s citations rank in the top 30% of the 100,000 most cited scientists in the world.


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