Section 21 of the Road Traffic Act 2002 provides the legislative basis for the use of cameras and other apparatus for the purpose of establishing evidence in respect of specified road traffic offences. The offences covered by this provision include offences under section 35 of the Road Traffic Act 1994 relating to general control of traffic. These include the offence of failure to obey traffic lights. I commenced this section of the 2002 Act with effect from 31 October 2002 under the Road Traffic Act 2002 (Commencement) (Order) 2002 SI 491 of 2002).