A thesis submitted in partial fulfillment of the requirements for the Degree of Master of Engineering, School of Engineering and Technology

Thesis (M.Eng.) - Asian Institute of Technology, 1979

Traffic signals are traffic control devices whose general function is to regulate traffic, to warn motorists of hazerds, and to guide traffic into correct position and safety. Uniform meaning and shape of display are important to the road user to help drivers assess an unfamiliar situation. In 1968, the United Nations held a conference on road traffic and produced a "Convention on Road Signs and Signals" as a guide to achieve a new worldwide uniform standard for traffic control devices. The present research was conducted to compare traffic control devices: layout and signal display of traffic signal devices from ten countries in Asia, two countries in Europe, and from Australia, to know how uniformity has been achieved on the basis of the 1968 UN Convention. Additionally, study was made of national standards as those of the Standards Association of Australia (1975), (Australia Standard 1742, Manual of Uniform Traffic Control Devices, Part 1-1975, and Draft Australian Standard, DR 75024, Manual of Uniform Traffic Control Devices, Part 2-1975); United States Department of Transport (1971) (Manual on Uniform Traffic Control Devices for Streets and Highways); and European Conference of Ministers of Transport (1971) (European Rules Concerning Road Traffic, Signs and Signals). The data were collected by using questionnaires sent by mail to the countries. The results of the research show: (a) that for many aspects, similarities of practice exist which could form the basis for an international standard; (b) layouts of signals, height of signal lanterns, and arrangement of signal lenses are recommended in this thesis; and (c) important differences exist which require early attention and detailed in the thesis; e.g. meaning of green arrow displayed and associated movement. Finally, it is suggested that the United Nations ESCAP conduct further research in traffic signal devices for building a Manual on Uniform Traffic Signal Devices for Asia and an Operating Guide of Manual Traffic Signal Devices for Asia, the region from where most of the data were collected.