GovWire

We received a request under the Freedom of Information Act 2000 on 10 November 2011:

This request relates to the Redfusion automatic speed detection system and the conditions of the Home Office type approval for said system. The Home Office decreed that a secondary, independent speed check be built into the system. Please can you supply all detail relating to the specification of the independent secondary check including but not limited to how the system may be incorporated, full type approval of the secondary system, when it was approved, whether it is a requirement to produce the secondary speed check as evidence in court, etc.

This information was released on 28 November 2011 in response to request 20653:

As set out in Section 5.4 of the Automatic Distance / Time Speedmeter Handbook (Second Edition) Provisional (attached), the second speed measurement must be within 10% of the primary speed measurement. The secondary check is accomplished by an independent free running clock. The secondary speed measurement was assessed during the course of type approval testing. The secondary check is not separately type approved, but approved as part of the whole RedFusion system. The Minister signed the order on 5th January 2010 granting type approval for the RedFusion speedmeter from 18th January 2010.

There is no requirement to present the secondary speed in court: The only requirement is to produce a violation record. Only the primary speed is shown on the violation record, but because the primary and secondary timestamps and the baseline distance are shown, the secondary speed is readily calculated. If the RedFusion Court Viewer application is used to present the evidence, both primary and secondary speeds are displayed.