Traffic Light Green Wave (2D)

This 2D companion to the 3D green-wave scene lays a straight arterial road flat with a chain of signals whose green-phase offsets are computed directly from each signal's distance divided by a chosen design speed. A live space-time diagram below the road plots distance against time so the resulting green corridor is visible directly: cars driving at the design speed thread every light on green, while a mismatched speed drifts out of the corridor and starts hitting reds. Adjust the design speed, your own driving speed, the cycle length, green share and signal count to see exactly how signal-timing coordination — not car-following behaviour — is what produces (or breaks) a green wave.