Guidance

Road traffic devices: guidance for police and manufacturers

Information on road traffic devices, such as breath-testing, speed cameras and immobilisation devices.

Applies to England, Scotland and Wales

Breath-testing devices

In June 2004, we published a guide to type-approval procedures for breath-alcohol screening devices used for law enforcement in Great Britain. The guide is a reference for manufacturers wishing to develop new devices.

In June 2013, we published a guide to type-approval procedures for evidential breath-alcohol analysis instruments used for law enforcement in Great Britain.

This guide provides, for the first time, for the type-approval of mobile devices. These are devices that can be used to carry out evidential breath-alcohol tests elsewhere than in a police station, for instance at the roadside.

The guide does not affect the type-approved status of any devices that have already been type-approved, nor does it require the further testing of those devices. If any already approved device requires further testing, for example, in the event of a modification, such testing will be carried out in accordance with the existing version (version 1, 2004) of the guide.

The guide gives a description of the technical requirements that need to be met in order to be considered for type-approval for use by police in Great Britain.

The code of practice for preliminary impairment tests (PDF, 175 KB, 12 pages) is designed for the use of police officers trained and authorised to carry out preliminary impairment tests to determine whether a person is unfit to drive and whether or not the unfitness is likely to be due to drink or drugs.

Drug-testing devices

In May 2012, we published a guide to type-approval procedures for preliminary drug testing devices used for transport law enforcement in Great Britain. The document is a reference for manufacturers wishing to develop new devices.

In September 2013, we published a copy of the guide to type-approval procedures for mobile preliminary drug testing devices used for transport law enforcement in Great Britain. This guide provides for the first time for the type approval of mobile devices, that is devices that can be used to carry out preliminary drug testing elsewhere than in a police station, for instance at the roadside.

Manufacturers can submit devices to the Home Office for testing and if the specifications are met, the device could then be approved by the Home Secretary for use by police.

Once a screening device is approved, officers will be able to use it to test if a person has a specific level of a drug in their system and then take a blood sample if the device gives a positive reading. This will enable suspects to be dealt with quicker, cutting bureaucracy and allowing officers to get back to frontline duties.

Currently, a medical examiner must be called out to assess if suspects are impaired because of drugs and authorise a blood sample.

The potential devices will test for a range of drugs including cannabinoids, cocaine, amphetamines, methylamphetamine, methadone and opiates.

View the complete list of drug-testing devices.

Speed cameras

Evaluation of the safety camera partnerships over the 4-year period from April 2000 to March 2004 identified their success in reducing speeding and the resultant casualties. The evaluation found that vehicle speeds had been reduced by 70% at new fixed camera sites and by 18% at new mobile sites.

Reductions in the proportion of vehicles breaking the speed limit by 15 miles per hour or more were even greater. Both casualties and deaths were down after allowing for the long-term trend, but without allowing for selection effects (such as regression-to-mean) there was a 22% reduction in personal.

View the complete list of speed detection devices.

In February 2009, we sent a letter to the chair of ACPO road policing enforcement technology committee to clarify the position regarding type-approval of traffic law enforcement devices and the consequent admissibility in court of evidence from such devices.

Read the letter to ACPO regarding type-approval and evidence.

Immobilisation devices

There are currently 2 approved immobilisation devices:

Published 26 March 2013
Last updated 7 April 2017 + show all updates
  1. Code of practice for preliminary impairment tests updated.

  2. Guide to type-approval procedures for evidential breath-alcohol analysis instruments published.

  3. First published.