Motorists can face an allegation of speeding in three different ways by virtue of the Road Traffic Regulation Act 1984. Firstly, temporary speed restrictions can be imposed with regard to road works and contravention of the temporary speed restriction is an offense. Secondly, contravention of a speed limit relating to a motorway is an offense. Thirdly, apart from motorway speeding offenses, any motorist who contravenes a speed limit commits an offense. Recent case law has clarified that the prosecuting agency in the case of a temporary speed restriction can elect as to whether to prosecute for breaching that restriction or a speed limit.
A motorist prosecuted for a speeding offense cannot be convicted solely on the opinion evidence of one witness to the effect that the motorist was driving a vehicle at excess speed. This means that any motorist prosecuted for a motorway speeding offense or for contravening a temporary speed restriction at road works can be convicted on the unsupported opinion evidence of a police officer provided, of course, that the court is satisfied beyond a reasonable doubt that the officer’s opinion of excess speed is correct. Recent case law has confirmed that where the prosecuting agency can elect to prosecute for contravention of a temporary speed restriction at road works, it would be tidier and more sensible to deal with the issue as contravening a speed limit as there would be protection of the motorist by virtue of the need for the officer’s opinion evidence to be supported by other evidence.
The requirements to provide additional evidence supporting opinion evidence have proved to be a fertile source of litigation. The opinion evidence of two police officers speaking as to the speed of a vehicle at the same moment in time can support each other’s opinion evidence. However, supporting evidence is usually provided nowadays by technology such as the speedometer of a police vehicle, radar equipment, VASCAR or by a laser speed measuring device. Case law established many years ago that a motorist could be convicted on the opinion evidence of one police officer supported by the reading of a speedometer or other mechanical means, even though there was no evidence that the speedometer had been tested or calibrated. Similarly, case law has long since established that a reading from a radar gun can amount to reliable or proper support of the opinion evidence of a police officer even though the gun has not been checked against the known speed of a vehicle fitted with a calibrated speedometer. The Divisional Court in three recent cases has given consideration to the evidence requirements in the context of speed testing devices.
In R (on the Application of Bray) v Bristol Crown Court  it was held that the fact that a laser speed detection device had not been calibrated in accordance with the manufacturer’s instructions does not mean that the device is no longer of an approved type. Accordingly, it was held that the speed reading produced by such a device was capable of constituting support of the officer’s prior opinion as to speed. The Divisional Court also emphasized that the evidence from the device as to speed is only secondary evidence and it is the opinion of the operator of the device regarding the speed that is the primary evidence.
In Iaciofano v DPP  the Divisional Court held that a Police Pilot Provida in-car speed detection device is not an approved device. The court further ruled that it had not been open to the court below to find that it was approved based on evidence that it had been installed in several police cars. The Divisional Court quashed the motorist’s conviction for speeding but did remit the matter back to the court below for reconsideration.
Statute regulates the admissibility of certain evidence with regard to speeding offenses. A record produced or measurement made by a prescribed device shall not be admissible as evidence in proceedings for a speeding offense unless the device is of a type approved by the Secretary of State and any conditions subject to which the approval was given are satisfied. A ‘prescribed device‘ means a device of a description specified in an order made by the Secretary of State.
In Connell v DPP  the Divisional Court ruled that a police officer was entitled to support his opinion on access speed by reference to the reading given by the Police Pilot device despite the fact that it was an unapproved prescribed device. In that case, a police officer had observed C driving a motor vehicle on a road where the speed limit was 70 mph. In the officer’s opinion, C’s vehicle was traveling in excess of 90 mph. The officer followed C in his police vehicle for some time before stopping him. At the trial, the police officer gave oral evidence of his assessment of C’s speed and supported that evidence by reference to the Police Pilot speed measuring device that had been fitted to the police vehicle. That device indicated that C had been driving at a speed in excess of 90 mph. The Magistrates’ Court held that the approval requirements were not relevant to the issue and accordingly the evidence of the police officer was admissible. The Divisional Court upheld the Magistrates’ Court ruling.
The Divisional Court observed that the Divisional Court in Iaciofano would not, after quashing the conviction for speeding, have remitted the matter for reconsideration unless it thought that a conviction was possible on the basis of a police officer’s evidence of speed being supported by an unapproved prescribed device. .The Divisional Court noted that the police officer in the case had given unchallenged evidence as to C’s speed; that support for this could be found in the fact that the police officer had been travelling in excess of 90 mph and would from time to time have looked at his speedometer and that when stopped C had not challenged the police officer’s opinion as to speed.
The Connell case is an illustration of the Divisional Court’s recent approach to the requirements of evidence supporting opinion evidence. These requirements would not appear to be as prescriptive as some defense lawyers would seek to argue. All the court at trial needs to be concerned with is whether or not it is satisfied beyond a reasonable doubt of the opinion evidence of the police officer as to speed and that this evidence is supported by other evidence that the court considers being reliable so that it can be sure that the motorist was, indeed, speeding.