In Japan, the current volume and density of traffic in urban areas has reached significantly high levels. A primary difficulty is due to delays caused by cars having to stop at each intersection. In order to keep traffic flowing smoothly, a method has been adopted to coordinate signal controls that are adapted to various traffic situations over an entire road network. Because computer resources and memories for calculating signal control timings are limited, the timings explained in this paper are prepared signal control patterns for various traffic situations, and the patterns are selected by the flow of traffic. This paper reports on a method for coordinated signal controls which are based on maximising bandwidths and can be run in real time. This method considers link speed in order to deal continuously with a variety of traffic situations.
Abstract