Electrical control of road traffic by vehicle actuation

The author discusses the control of road traffic by traffic officer and by time-controlled. signals, and from their advantages and limitations deduces the fundamental requirements of a system operating automatically by vehicle actuation. These requirements, which arise directly from the problem of ensuring adequate safety with maximum traffic circulation at road intersections of widely diverse characteristics, are enumerated, and a detailed description is given of a method by which they are attained in practice. The method employed is shown to combine to a high degree the flexibility and immediate response of the best type of officer control with the definite and highly visible indication of signal control. Methods by which the basic system may be modified to meet special cases are also dealt with, and the author concludes by indicating that control must shortly be considered in relation to complete areas rather than to the single intersection.