Signal coordination
Discover how signal coordination along a road minimises stops and delays.
Overview
Signal coordination is the linking together of consecutive traffic signals along a road to minimise stops and delays.
It is important to prevent blockages between closely-spaced intersections or when traffic becomes congested. Coordination can also be achieved within grid networks, like Melbourne’s CBD.
To maintain synchronisation, all coordinated intersections must operate at the same cycle time.
Signal coordination is shown through a time-distance diagram, like the one below. Time is in the vertical axis and distance along the horizontal axis. The duration of the green and red lights facing the main road are shown. The green band shows how traffic in one direction gets through multiple intersections without stopping.
The time from the start of green at one intersection to the start of green at the next intersection is known as the linking offset. In morning and afternoon peaks, linking offsets may be selected to favour traffic in the peak direction.