In traffic terminology, what does 'phase' refer to?

In traffic terminology, a 'phase' refers to the complete sequence of changes a traffic signal undergoes. This encompasses all the lights and turns relevant to traffic control at an intersection, including green, yellow, and red signals for various directions. Each phase allows specific movements, directing which vehicles or pedestrians can proceed safely at any given moment.

For instance, during one phase, the traffic may proceed in one direction while other directions are halted. This process is crucial for managing traffic flow efficiently and ensuring safety at intersections. Understanding traffic phases is vital for transportation engineering and signal design; it impacts congestion, delays, and overall traffic safety.

The other options do not capture the full functionality of a phase as they focus on more narrow aspects of traffic signal operation, such as only the duration of the green light or merely the stopping time at red lights, thus missing the broader context of traffic signal sequences.