How a green wave works
On a coordinated street, traffic signals are timed so that a driver moving at a chosen speed can reach a series of intersections as each light turns green. The offset—the delay between one signal’s cycle and the next—creates a moving window of green lights. It is less like one giant signal and more like a sequence that rewards a fairly steady pace.
That timing is usually designed around motor traffic, not a particular bicycle messenger. A cyclist may travel at a different speed, and a red light, congestion, or a change in traffic can break the sequence.
Reading the street, not just the clock
Experienced couriers can learn the rhythm of familiar routes: where a green is likely to end, how long a stretch takes at a sustainable pace, and when it makes sense to ease off rather than sprint toward a red. Holding a steady speed can sometimes bring the next intersection into reach during its green phase. This is the practical meaning of “surfing” a green wave.
The skill is not simply memorizing exact delays. It is combining route knowledge with constant adjustments to what is happening ahead. Signal timing offers a pattern; it does not override cross traffic, turning vehicles, pedestrians, or the need to stop when the light is red.
Why the rhythm matters
A cyclist who anticipates a signal may avoid needless bursts of speed and braking, making a trip smoother when conditions cooperate. But no cadence can guarantee an uninterrupted ride across a city. The wave is a useful opening in the timing of traffic—not permission to ride through an intersection before it is safe.
