1. This Order may be cited as the Road Traffic Offenders (Prescribed Devices) Order 2008 and shall come into force on 16th June 2008.

2. In this Order—

“odometer pulses” means the signals derived from sensors in a motor vehicle monitoring either the rotation of a wheel or wheels or the final component of the vehicle which transfers power from the engine to the wheels, such as an axle, at a rate which is proportional to the distance travelled by that vehicle.

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.