Graphical Optimization Method for Symmetrical Bidirectional Corridor Progression

Algorithm 1

Initialization procedure.

	Our first step is to define and calculate some basic parameters, and the initialization routine can be presented below.
	Initialization procedure
	Step0. Determine the range of the common signal cycle [Cmin, Cmax] and calculate the initial common signal cycle C1 = 0.5(Cmin + Cmax).
	Step1. Make a judgment of whether the progression design speeds of all road sections equal the corridor progression design speed or not. If there is an inequality, calculate the intersection adjusted distance Dp for the corresponding road section as shown in Equation (1).
	Step2. Determine the range of adjusted speed V(i, j) obtained after the jth rotation transformation in the ith round, as shown in Equation (2).