Optimal division of signal-coordinated arterial street into subareas

This study proposes a method for optimally dividing the signal-coordinated arterial street into subareas with different cycle length and describes the features of optimal division showing some examples of calculation．The optimal division into subareas and the optimal cycle length for each subarea are obtained by the DP technique．The optimal offsets for each subarea are also obtained by DP．Therefore，DP is applied two times．Among the three parameters of cycle length，split and offset，the splits are treated as given．A weighted sum of delay and stops is used as a performance index for optimization．Traffic conditions are assumed to be undersaturated and a platoon to be represented by a single rectangular wave．From some examples of calculation，the following has been made clear about optimal division into subareas: if there are no large differences in splits，road and traffic conditions among intersections，division into subareas should not be made．If there are differences in these condition，areas including signals with smaller splits or areas with heavier traffic should be controlled with a longer cycle length than those of the other areas，and the whole street should be divided into subareas according to link lengths and that arrangement．

cycle length

offset

delay

dynamic programming