Street traffic signals, with particular reference to vehicle actuation

The author describes current practice in street traffic signalling, dealing particularly with vehicle-actuated signals as adapted for use in Great Britain. Detailed descriptions are confined to the system with which the author is most familiar (the Autoflex vehicle-actuated system). Brief references are, however, made to other systems and to practice in other parts of the world. All parts of the equipment are treated, including signals, controllers, and detectors. The paper is divided into two main portions, the first dealing with generalities and isolated intersections and the second with interlinking of numbers of intersections. The subject is treated from the traffic aspect as well as from the electrical aspect, and details of the performance of certain of the schemes are given.