Briefly describe the different ways the traffic signals at the intersection of an arterial route could be coordinated, stating under what conditions you would use each of them.

Question

What will be an ideal response?

Answer 1

Traffic signals can be coordinated by several methods: simultaneous
system, alternate system, and progressive system. In a simultaneous system, all
signals have the same cycle length and are in the green phase for the arterial at the
same time. This system works best when intersections are approximately the same
distance apart. In an alternate system, intersections are formed into groups where
successive groups alternate green phases. The alternate system works best when
the intersections within a group are at equal distance from each other. In a
progressive system an offset is introduced between the start of green for the
arterial at one intersection and the start of green for the arterial at the succeeding
intersection. This offset is based on the distance between intersections and the
speed of traffic. This method best accommodates variable spacing between
intersections and heavy directional flows.