Each signal has a red, yellow, and green period. These are "phase
s." It may also have a phase for a turning movement, an all-red phase for pedestrian
s, or a phase for bicycles.
Cycle Length: The time it takes for the signal to go through all the phases (green, yellow, red, and back to green) is the cycle length.
Green time: The length of the green phase.
For each "simple" intersection of two roads crossing at 90 degree angles, there is a "major" street and a "minor" street. The major street carries more and probably heavier traffic, and is usually wider. A major street can become a minor street if it crosses a more significant intersection. The engineer studies the volume and congestion levels to decide the amount of green time to give each approach. If a heavily traveled bus and truck route crosses a local street, the engineer is likely to set the more significant street's green phase to 70% or more of the cycle length, but if there isn't much of a difference, a 55/45 split is more likely.
So, if you're traveling a long distance, you're better off taking a major street. Each time you approach a more major cross street you'll have less green time.