# The Road Traffic Offenders (Prescribed Devices) Order 2008, Article 3


The following device is prescribed for the purposes of section 20 of the Road Traffic Offenders Act 1988 (speeding offences etc: admissibility of certain offences), that is to say, a manually activated device designed or adapted for recording the measurement of the speed of a motor vehicle (“vehicle A”) from another motor vehicle (“vehicle B”) by—
(a) measuring the time taken by vehicle A to pass two positions on the road either directly or by reference to the time taken by vehicle B to pass the same two positions on the road;
(b) recording the distance between the two positions by counting the odometer pulses from vehicle B as it travels between the two positions; and
(c) calculating the average speed of vehicle A over the distance between the two positions by reference to the time recorded in sub–paragraph (a) and the distance either calculated in accordance with sub–paragraph (b) or measured manually.

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Source: https://www.legislation.gov.uk/uksi/2008/1332/article/3 (the official version)
Page: https://openlegislation.uk/road-traffic-offenders-prescribed-devices-order-2008/article-3
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.