A traffic Capacity Research for Five-way Roundabouts with Signal Controls

摘要

Roundabouts that boast safe and smooth traffic flowing have been extensively utilized. Yet as simple roundabouts are not sufficient to cope with the increasing traffic volume, it is necessary to carry out programs on signalized roundabouts. Due to the fact that existing domestic researches on the capacity of roundabouts are limited to regular four-way models, this paper explores a capacity model of five-way roundabouts with signal control. First of all, the author would optimize the existing signal timing of a certain five-way roundabouts with the signal optimization model. Secondly, the author calculates the capacity of each road entry by dividing the entries into major and minor ones based on their traffic volume and quantity of lanes. Then the capacity of each entry is to be added up to get the total capacity of the roundabouts. Last but not least, the Wujiaochang five-way roundabout of Shanghai is taken as a case study for the test of the capacity model, and the result proves that this model presented in this paper enjoys excellent performance.