I. INTRODUCTION[1]
Urban trunk road is the main urban transportation undertaker, the intersection of the trunk road become the traffic capacity’ bottleneck, the traffic signal of several intersection of arterial road will be controlled in coordination, which can improve the traffic capacity of turning vehicle will be disturbed and crossed by the opposed straight vehicle, the traffic capacity is deduction, and the traffic order is chaos. Therefore a special left-turning phase should be added, that is four phase signal control. Among them the first phase indicates Huaihai south arterial road greatly. There are two traditional design method of Urban trunk road's coordination control: one is the graphic method, and the second is algebraic method. Graphic method is using the geometrical graph method to get the approximate solution which based on the time-distance figure; But the algebraic method is through looking for the minimum phase difference to obtain optimal control scheme These two methods are simple, and the use is more extensive.