PURPOSE: To determine the proper length of a road occupying section and to properly set up a road construction process in the determined road occupying section.

CONSTITUTION: In the case of setting up a part of the width of a road as a road construction occupying section, respectively arranging temporary signals on extensions from both the ends of the section, and moving the road construction occupying section along the road in accordance with the advance of the road construction while executing single side traffic regulation for vehicles on the remaining part, the green signal ON time of respective temporary signals is determined based upon previously determined two-way vehicle traffic volume data on the road, the length of the section is determined by comparing the rate of vehicle arrival with the allowable number of waiting vehicles, the maximum excavatable distance in the section concerned is found out while considering a previously determined safety distance, and a construction cycle period is found out based upon the found distance.