MIGRATION TO TRAFFIC ADAPTIVE CONTROL : A CASE STUDY

Many of the urban traffic control systems currently in operation around the world are based on first generation control technology, and for various reasons, they are now in need of renewal. These systems lack the ability to react in real time to the fluctuating driving demands. Modern advances in traffic control technology have made available this traffic adaptive capability, but at a cost measured in terms of capital investments and increased complexity. Based on experiences from an actual renewal project in Hong Kong, this paper examines the key issues for consideration in upgrading traffic signal control systems, including the assessment of the need for traffic adaptive control, deciding whether to upgrade or to replace the existing system, and specifying the new system to minimize implementations risks and changeover times, as well as to ensure future competitive supply on equipment, in particular signal controllers.