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Driving Under Influence: Drugs

Volume 492: debated on Friday 8 May 2009

To ask the Secretary of State for Transport how many fatal road traffic accidents involved a person (a) whose driving ability was impaired by illegal drugs and (b) who tested positive for illegal drugs in each of the last five years. (273811)

The number of fatal road accidents where the contributory factor 'impaired by drugs' was reported by the police officer at the scene of the accident are given in the table:

Fatal accidents1







1 Includes only accidents where a police officer attended the scene and in which a contributory factor was reported

Information on contributory factors is only available from 2005. It is not possible to distinguish whether illegal or medicinal drugs were involved.

Information on whether a person involved in a fatal road accident tested positive for illegal drugs is not available.

To ask the Secretary of State for Transport (1) what recent assessment he has made of the performance of the Field Impairment Test in determining whether a person is fit to drive after taking illegal drugs; (273812)

(2) whether his Department has commissioned studies of the effectiveness of roadside drug testing in other countries; and if he will make a statement.

The most recent assessment of Field Impairment Testing is in the Department’s Road Safety Research Report No. 63—Monitoring the Effectiveness of UK Field Impairment Tests which was published in April 2006. It is available on-line at:

The Department has not commissioned any studies of roadside drug testing abroad. However, the EU’s Rosita-2 project evaluated the usability and analytical reliability of roadside drug testing devices in several European countries and the USA. The project report is available online at

It concluded that no device was considered sufficiently reliable in order to be recommended for roadside screening of drivers.