398.Sections 275 to 278 transfer the Secretary of State’s statutory functions for traffic control systems in Greater London to TfL for all roads other than trunk roads. (Traffic control systems can be defined as electronic systems which provide regulation, instruction, information or guidance to road users and to authorities from installations on or adjacent to the highway. They include traffic signals and signalled pedestrian crossings together with their associated control and monitoring computer systems, vehicle and pedestrian detectors, variable message signs, closed circuit television cameras, speed cameras and emergency telephones).  The sections provide for existing traffic signals, and their maintenance and operation, to be devolved to London borough councils. Such councils can also set up and operate new traffic signals, with TfL's consent.
399.The sections also provide for the transfer to TfL, from the Secretary of State (and vice versa) of traffic control systems in Greater London. Where the Secretary of State decides that he wants to pass to TfL the traffic control systems for a trunk road or roads in Greater London, he can transfer (i) all the systems relating to that road, and (ii) the maintenance and operation of those systems. The Act also provides for the transfer from TfL to the Secretary of State of the entire traffic control system for all the roads in Greater London and for this to be reversed  with the agreement of the Secretary of State and TfL. On all roads in Greater London other than trunk roads, wherever a traffic sign is a light signal, TfL is to be deemed to be the traffic authority for those roads in the application of sections 65, 73, 74, 74A and 75 of the RTRA 1984 to such traffic signs.
Commentary on Sections Part Iv: Transport Chapter Xiv: Road Traffic Sections 275 to 278: Traffic control systems in Greater London